From the Super Mario Wiki
Cheep Cheeps (Japanese プクプク Pukupuku) (sometimes formatted as Cheep-Cheeps or Cheep-cheeps) are fish that made their first appearance in Super Mario Bros. in the underwater levels. They are common recurring enemies throughout the Mario series. They are found mostly in the water but they can jump out of the water as well like in Mario Super Sluggers. There are many different species of Cheep Cheeps, and they come in different colors, including yellow and green. The most common ones, however, are red with a white patch on their stomach, a yellow (originally white) tail fin, a mohawk-like dorsal fin and wing-like fins. They also have blue eyes and pink lips. Cheep Cheeps have fins shaped like wings and may attack above the surface of the water by jumping out in an arc. Given this, Cheep Cheeps seem to be inspired by flying fish, who behave similarly.
Super Mario series
Super Mario Bros. / Super Mario Bros.: The Lost Levels
In Super Mario Bros. and Super Mario Bros.: The Lost Levels, Cheep Cheeps are found in the underwater levels, swimming towards the player, where they can only be defeated with a fireball, or if Mario is invincible. They are found in all of the water levels and can usually be seen with Bloobers. In some levels, red Cheep Cheeps jump up from the bottom of the screen, creating random obstacles. These can be defeated in a single jump, but it's hard to do so, as they jump very high. They often appear in pit-heavy areas, and can foul Mario's attempts to cross should they jump directly under him.
There are two kinds of Cheep Cheeps in the game. One of them is colored red and moves moderately fast. The other is colored gray (green in Super Mario All-Stars) and moves more slowly. In some levels, the red Cheep Cheeps grow wings and fly up from the bottom of the screen.
Super Mario Bros. 3
In Super Mario Bros. 3, Cheep Cheeps act the same, although they can also jump out of water and lava. They are mainly seen in Sea Side. Also, around this time, Cheep Cheep's tail fin color change from white to yellow, and the slow-moving Cheep Cheeps were recolored green (instead of gray). The game was also to include yellow Cheep Cheeps, which were to move even faster than red Cheep Cheeps and appear in trios, but they were taken out due to unknown reasons. This game also introduced infant and adult versions of Cheep Cheep - Baby Cheep and its mother, Big Bertha, as well as the feared Boss Bass. The NES manual refers to Spiny Cheep Cheeps simply as "Cheep-cheeps", describing them as thorny, and even shows artwork of a Spiny Cheep Cheep.
Super Mario World
In Super Mario World, they pose a numerous threat as the yellow, slow-moving fish found underwater and in floating bubbles, although they are only found in bubbles when they appear on land. If Cheep Cheeps are on land flipping around, Mario or Luigi can simply run into them to defeat them. They can also be defeated with a Cape, Yoshi, or fireballs.
Super Mario Sunshine
There are three varieties of Cheep Cheeps in Super Mario Sunshine. An orange variety is found in Ricco Harbor, Delfino Airstrip, and sometimes during the King Boo fight in Sirena Beach, a flaming, maroon variant lives in the lava in Corona Mountain, and a pink variety can be found in Noki Bay, Gelato Beach, and Delfino Airstrip.
The orange and charred varieties make huge leaps and can be defeated by either a jump or with F.L.U.D.D., and can also turned into platforms by Yoshi's juice. However, they will keep respawning. If King Boo spins three question marks on the slot machine during his battle, he may spit out two Cheep Cheeps, but they'll flop about upside down. The pink ones will actively hunt Mario down if he gets too close and they will catch Mario in their mouths, dragging him down deeper into the depths of the water but they don't hurt him. These Cheeps are invincible to all of Mario's attacks, and it's unknown if Yoshi can defeat them since they're found in deep waters that Mario typically can't reach with Yoshi. They have blue fins on their tails and back in this game, as well as blue spots on their undersides, as well as a slightly flatter body shape and they act similar to Super Mario World's Rip Van Fishes. Any variety is often confused with Bubbas but they are smaller in size and do not wear sunglasses.
Super Mario 64 DS
In Super Mario 64 DS, Cheep Cheeps replace Bubs in Dire, Dire Docks. They do not really pose a threat to the heroes, as they do not attack them. In this game, they appear to be orange, unlike most games where they are colored red.
New Super Mario Bros.
In New Super Mario Bros., Cheep Cheeps behave the same way as in other platformers and have a larger version. However, two subspecies were introduced: the Deep Cheep, Cheep Chomp and an unknown, purple one, similar to the Porcupuffer. Deep Cheeps and Cheep Chomps chase Mario when they appear on-screen. Deep Cheeps can't turn around, but Cheep Chomps can. The Deep Cheep also has a larger version. In World 2-4, a strange Cheep Cheep appears in a bonus area. It swims in a wavy line and trails six coins behind it. They also briefly turn toward the player if run into from behind.
Super Mario Galaxy
Cheep Cheeps reappear in Super Mario Galaxy, acting the same way as they did in older games. They only appear in the Deep Dark Galaxy, in the second and third missions. In the second mission, they appear on a small planet, half of which is covered in a thin layer of water, and bounce up and down around the planet. They can be defeated either with a spin or by jumping on them. One appears underwater in the third mission, which can only be beaten with a spin or Koopa Shell. They are also seen in the video at the end of the game, jumping out of the water near Princess Peach's Castle.
New Super Mario Bros. Wii
The red Cheep Cheeps behave just like they did in the original New Super Mario Bros..
The golden colored Cheep Cheeps, Eep Cheeps, are always found in schools, called Cheep Cheep Schools. They will also swim away from players whenever they get close, the complete opposite of the Deep Cheep's behavior. The Eep Cheeps seem to resemble the beta Cheep Cheeps of Super Mario Bros. 3.
Super Mario Galaxy 2
Cheep Cheeps reappear in Super Mario Galaxy 2, but are much more common than in the predecessor. They appear in water-themed galaxies such as Cosmic Cove Galaxy and Starshine Beach Galaxy, but they don't hop on land. They are now found swimming near the surface and can be defeated by a spin, jump, or by Yoshi's tongue. They can not be stunned with a Star Bit.
Super Mario 3D Land
Cheep Cheeps reappear in Super Mario 3D Land as underwater enemies in some of the levels, including some of World 3. They can also jump out of water. This time, stomping on a Cheep Cheep underwater won't harm Mario. Additionally, they can be flattened by using Ground Pound whilst underwater. They can also be defeated by fireballs, tail whips, boomerang hits, and turning into Statue Mario above them. They first appear in World 1-1 where they will attempt to hit Mario by jumping out of the water.
New Super Mario Bros. 2
Cheep Cheeps reappear in New Super Mario Bros. 2, where they jump out of water trying to harm Mario or Luigi. After the Mario brothers touch a Gold Ring, Cheep Cheeps (among other enemies) will turn golden. In this state, they are followed by a row of five coins.
New Super Mario Bros. U
Cheep Cheeps reappear in New Super Mario Bros. U. They behave exactly like in past titles. Jumping Cheep Cheeps also appear, as well as the Eep Cheeps. There is also a new type of Cheep Cheep, known as the Mecha Cheep, that appears in underwater airships. They seem to be mechanical, and they use propellers on their fins to move forward.
Super Mario 3D World
Nintendo Adventure Books
As Luigi and Toad are exploring Water Land in Leaping Lizards, some Cheep Cheeps jump from the water to try and attack them, but most are avoided; some of the fish also appear three weeks later among the crowds at the International Mushroom Games. In Pipe Down!, Ludwig von Koopa will sic some Cheep Cheeps on the Mario Bros. if they attempt to attack him directly during one portion of the book, and some will attack Mario along with some other monsters if he pulls the wrong nob on Ludwig's giant pipe organ.
If Mario, Luigi, Toad and the Mushroom King are run down by a group of Dino Rhinos in Flown the Koopa, they will lose their tickets to the International Dino-Flying Derby, which will end up being blown into a tree inhabited by Cheep Cheeps by a gust of wind. If Mario is chosen to get the tickets back, he will succeed, stomping the irritated Cheep Cheep he takes them from. If Luigi tries to get the tickets instead, a Cheep Cheep will bite him and cause him to fall out of the tree and into a patch of Munchers, causing a Game Over.
Mario Kart series
Super Mario Kart
Cheep Cheeps first appear in the Mario Kart series, Super Mario Kart. They appear as enemies along with Thwomps, Piranha Plants, and Monty Moles. Cheep Cheeps appear in two races, Koopa Beach 1 and Koopa Beach 2. In the courses, they are obstacles that the player must dodge. A Cheep Cheep balloon holds the trophy during the award ceremony.
Mario Kart 64
After appearing as enemies in Super Mario Kart, a Cheep Cheep appears as an enemy in Mario Kart 64. A giant Cheep Cheep appears in the course Banshee Boardwalk. This Cheep Cheep tries to swallow the passing racers that drive by. Similar to Super Mario Kart, a Cheep Cheep balloon holds the trophy during the award ceremony.
Mario Kart: Super Circuit
Cheep Cheeps appear as non-playable characters in the Game Boy Advance game, Mario Kart: Super Circuit. In this game, they have a course named after them, called Cheep-Cheep Island. Larger Cheep Cheeps can be seen jumping in the background here. Koopa Beach 1 and Koopa Beach 2 from Super Mario Kart appear in this game, but the Cheep Cheeps are absent due to both being Extra tracks.
Mario Kart DS
Cheep Cheeps, again, make non-playable appearances in the Nintendo DS game, Mario Kart DS. In this game, Cheep Cheeps have a course named after them, called Cheep Cheep Beach. Koopa Beach 2 returns, with Cheep Cheeps appearing as hazards. Banshee Boardwalk also returns, but the Cheep Cheep is replaced with a Boss Bass. In mission 1-4, Wario must storm through five Cheep Cheeps with a Star.
Mario Kart Wii
In Mario Kart Wii, Cheep Cheeps make cameo appearances. In the course, Koopa Cape, when the player enters the underwater tunnel, Cheep Cheeps are seen in the background. Unagis can also be seen with them. Also, the Cheep Charger is a Kart that resembles Cheep Cheeps for light-weighted characters.
Mario Kart 7
Mario Kart Arcade GP DX
In Mario Kart Arcade GP DX, a few Cheep Cheeps appear in the underwater section of one of the courses.
Mario Kart 8
Super Mario Land 2: 6 Golden Coins
Super Mario Land 2: 6 Golden Coins again features Cheep Cheeps. Cheep Cheeps hinder Mario's progress through the Macro and Turtle Zones by swimming back and forth in the water, like a Goomba. Among the other fish, they are accompanied by similar-looking Blurps. They can be destroyed by a tossed Green Shell or a fireball.
Cheeps Cheeps appear in several Yoshi games, though they are named Flopsy Fish in the English versions. They make their first appearance in Super Mario World 2: Yoshi's Island (pictured at right) and reappear in Yoshi's Island: Super Mario Advance 3, Tetris Attack (as a character, paired with a Lunge Fish), Yoshi Touch & Go, and Yoshi's Island DS. They are a bit bigger than in most games and either jump out of water or just swim around. A more aggressive version repeatedly jumps out of the water with its mouth open. They can't be turned into eggs if Yoshi eats them. The level "Lake Shore Paradise" has one of them as a map screen icon. In Yoshi Touch & Go, a blue, spiky version similar to a Spiny Cheep Cheep appears that has not been seen since. Similar enemies, called Blurps, appear in Yoshi's Story. Here, instead of wearing goggles as they do regularly, their appearance is similar to Cheep Cheeps'.
Super Mario RPG: Legend of the Seven Stars
In the English version of Super Mario RPG: Legend of the Seven Stars, Cheep Cheeps appear under the name Goby. They are actually Cheep Cheeps, as they share the same Japanese name (Pukupuku). Gobies dwell underwater in Kero Sewers. They roam the waterways, battling intruders who invade their territory. In battle, a Goby will lower its head and ram into its enemy. Gobies have no special attacks, and they are weak against lightning-based magic attacks.
Unfortunately for the Gobies, the water of Kero Sewers can be drained, which is exactly what happens during the events of Super Mario RPG: Legend of the Seven Stars. Without water, Gobies flop around erratically on the dry ground. However, when engaged by an attacker, Gobies will use their fins as wings, allowing them to fly for short periods of time. While flying, Gobies attack in the same way as they do when swimming. Gobies also have green-skinned relatives called Mr. Kippers.
Paper Mario series
In the Paper Mario series, Cheep Cheeps are considerably more intelligent than their predecessors, and are able to speak, as well as safely live and travel about on land. As indicated in Paper Mario: The Thousand-Year Door, many even have jobs, such as blimp conductor and chef. The most significant of these land-dwelling fish is Sushie, a female Cheep Cheep who is among Mario's many partners in Paper Mario.
Cheep Cheeps also appear as enemies in Super Paper Mario, though they are allies in the first two games. A Shayde from The Underwhere told another of his species about how he lost his game and mentioned that he swam like a Cheep Cheep and lost by being eaten by a Boss Bass.
Paper Mario: Sticker Star
Cheep Cheeps return as enemies in the Nintendo 3DS game Paper Mario: Sticker Star. In this game, they are only red, unlike in Super Paper Mario where they were also green. Cheep Cheeps only appear in Whitecap Beach, where they jump out of the water, or poisoned water if Gooper Blooper hasn't been defeated. In this game Cheep Cheeps like poison just like Snifits. They have the same HP as Spinies do and can be defeated without battling them however, they will respawn no matter what. In battle, they can either slam into Mario or shoot a jet of water. Failure to block this attack will have around a 75% chance that could give Mario the Soggy status effect.
Mario Golf series
Cheep Cheeps do not make a physical appearance in Mario Golf: Toadstool Tour but instead have a course named after them, Cheep Cheep Falls. However, Cheep Cheeps actually appear in Mario Golf: World Tour swimming around the Cheep Cheep Lagoon course.
Mario & Luigi: Superstar Saga
In Mario & Luigi: Superstar Saga, Cheep Cheeps appeared as enemies at the Oho Ocean. They had the same coloration as in Super Mario RPG: Legend of the Seven Stars. If the player jumps on them, they turn into Puffer-Cheeps, Cheep Cheeps covered in spines.
Mario Party series
Mario Party 4
Mario Party Advance
In Mario Party Advance, there are two Cheep Cheeps that appear in Shroom City. One of them is golden, and is a swim coach; the other is the normal red color and is the swim student. Upon arriving at the Mushroom Pool, the coach tells the player that his student was lacking in confidence, and asks if the player will race him; however, the player has to lose, but make it look convincing. After succeeding, the coach rewards the player with the Gaddget Desktop Golf. The ending states that Cheep Cheep had improved, even setting a record, and that the coach wrote a book about his confidence techniques.
Mario Party 7
In Mario Party 7, Cheep Cheeps appear in many minigames, including Fish & Cheeps, Bridge Work, and Be My Chum!. There is also a Cheep Cheep in the Grand Canal that will squirt a player who lands on its Green Space (which is in front of what looks like the Leaning Tower of Pisa) back to the start.
Mario Party 8
Cheep Cheeps make two cameo appearances in Mario Party 8. One is in the minigame Rowed to Victory. They appear in the background watching the players row their boat. After that they assist a Mega Cheep Cheep in chasing the losers. Also they appear as one of the pictures in Picture Perfect.
Mario Party DS
In Mario Party DS there is a minigame called Cheep Chump, where the player must prevent their character from getting sucked up by a Cheep Cheep. There is another minigame called Cheep Cheep Chance, where the player must choose the rope with the Cheep Cheep on it.
Mario Party 9
In Mario Party 9, a giant Cheep Cheep is one of the bosses that appear in the game. It is the mini-boss of Blooper Beach. The Cheep Cheep is faced in the minigame Cheep Cheep Shot, in which the players must attack the Cheep Cheep by tossing shells at it while avoiding its attacks, which are charging directly at a player, or by diving at the players from the air.
Cheep Cheeps also make minor appearances in the game. In the minigame Pianta Pool, Cheep Cheeps appear to leap through the rings the players grab. Three leap through a pink ring, while five leap through the golden ring. Additionally, in the minigame Pier Pressure, players attempt to grab the lines that have Cheep Cheeps on the end. Players are allowed to continue competing as long as they fish up a Cheep Cheep. A Cheep Cheep is also on one of the puzzles to be solved in the minigame Jigsaw Jumble. Additionally, Deep Cheeps from New Super Mario Bros. Wii can be seen jumping over the water in Blooper Beach.
Mario Party: Island Tour
Mario Party 10
Super Princess Peach
Cheep Cheeps appear in Super Princess Peach, where they act similar to the Flopsy Fish in Super Mario World 2: Yoshi's Island and Yoshi's Island DS. They can be defeated simply by jumping on them. A sub-species under the spell of the Vibe Scepter are the Sad Cheep Cheeps.
Mario Super Sluggers
Super Mario World: Mario & Yoshi's Adventure Land
A Cheep Cheep is one of the (incorrect) choices in a question. It doesn't appear anywhere else in the video.
Augmented Reality Games
Cheep Cheeps can be caught in the Fishing minigame if the Question Block AR Card is placed on a red surface.
Cheep Cheeps also make a cameo in Lego City Undercover, in which they appear if the player goes fishing when not required.
According to Paper Mario: The Thousand Year Door, Cheep Cheeps have their own language, which is also called "Cheep Cheep". This language is presumably spoken only by Cheep Cheeps and it is only partly heard through the character Chef Shimi (who often mixes words, such as "saved" and "shaved", up due to his unique language knowledge). However, in Paper Mario, the letter Sashimie wrote to Sushie is written in Mario's language.
In the Super Mario Bros. instruction booklet, Cheep Cheeps are explicitly referred to as female. This makes them the first generic Mario enemy to be entirely female. However, this has changed since the Paper Mario series, in which both male and female members of the Cheep Cheep species have appeared. The Cheep Cheep boss of Mario Party 9 is also referred to as male in the minigame description.
Trophy information from Super Smash Bros. Brawl
Names in other languages