Cheep Chomp

Cheep Chomps (originally parsed Cheep-Chomps ) are Cheep Cheeps that are bigger than usual and are first found in underwater levels in New Super Mario Bros. They closely resemble a Boss Bass. These Cheep Cheeps are purple with a turquoise back-fin and have enormous mouths and squinting pupils.

New Super Mario Bros.
In New Super Mario Bros., if Mario or Luigi swim too close to the Cheep Chomp, it follows him, opens its mouth, and tries to eat him. If they eat players, they lose a life, regardless of their condition. They can be defeated, like all other fish, with a Fireball or as Mega Mario/Luigi. Only three appear in the entire game, all of them appearing in the same level: World 3-1.

New Super Mario Bros. Wii
In New Super Mario Bros. Wii, only two Cheep Chomps appear: Once in a bonus area in World 4-4, and again in a bonus area of World 9-2. A Fireball or Starman can defeat Cheep Chomps, but they are invincible to ice balls from Ice Mario. Two changes are made from New Super Mario Bros.: it is slightly bigger, and defeating it releases three 1-Up Mushrooms.

New Super Mario Bros. 2
Cheep Chomps once again appear in New Super Mario Bros. 2. One makes it first appearance early in World 1-5. When defeated, it releases 3 coins. They reappear as common enemies in World 4-5. Another appears in course 1 of the Impossible Pack, near two whirlpools.

New Super Mario Bros. U
The Cheep Chomps reappear in New Super Mario Bros. U and act as in the predecessors. This enemy is prominently featured in the Superstar Road level Swim for Your Life!, where it must be used to eat Urchins and other enemies to complete the level. This time, it takes three hits from a fireball to be defeated, unlike earlier titles, where it took only one. However, like a Porcupuffer, it returns shortly afterward.

New Super Luigi U
In New Super Luigi U, Cheep Chomps appear in Cheep Chomp Chase in Acorn Plains and Star Coin Deep Dive in Superstar Road. Cheep Chomps, Magmaarghs, and Magmaws are the only enemies who can defeat Nabbit.

Paper Mario: Sticker Star
A giant Cheep Chomp appears in Paper Mario: Sticker Star as an obstacle. It can be seen on the surface of the water in Long Fall Falls, pursuing Mario (who is riding a raft down the river). The Cheep Chomp appears to be made of cardboard, featuring a propeller-like tail. The Cheep Chomp can destroy parts of the raft Mario is riding on by ramming into it, and being eaten results in an instant Game Over. When both reach a waterfall, Mario and his raft continue to fall, while the Cheep Chomp's "propeller" ends up propelling it upward, into space.

Mario Party: Island Tour
Cheep Chomps appear in Mario Party: Island Tour in the minigame Cheep Diamonds. They swallow an amount of diamonds and then circle around in the water; the players are trying to pick the Cheep Chomp that swallowed the most diamonds.

Mario Party 10
In Mario Party 10, a Cheep Chomp named "Mega Cheep Chomp" (巨大 バクバク, Kyodai Bakubaku) appears as a boss. Its minigame, Mega Cheep Chomp's Shell Shock, involves the players firing Koopa shells from cannons at it to deal damage. Each player has three Koopa shells, and they try not to have the Mega Cheep Chomp face them when time runs out, otherwise resulting in the Mega Cheep Chomp lurching out of the water and landing on the player it is facing, deducting points. Every time a player hits him with a Koopa shell, it rotates, changing the player it will attack. When it is mad, three Cheep Cheeps will appear and swim around it, deflecting shots from cannons. They can be eliminated by shooting shells at them.

Trivia

 * The New Super Mario Bros. Wii Prima Guide incorrectly refers to the Cheep Chomp as a Porcupuffer.