Porcupuffer

Porcupuffers (called Porcu-Puffers in Super Mario World) are a species of large, garishly-colored Cheep Cheeps that first debuted in Super Mario World. They resemble gigantic indigo Cheep Cheeps with red lips and blue, cyan, and yellow spikes all over their back. Their faces are nearly identical to those of Boss Bass, Big Berthas, and Cheep Chomps, but unlike them, they never try to eat Mario. Their name is a portmanteau of "porcupine" and "pufferfish".

Super Mario World
Porcupuffers appear in Super Mario World, where they follow Mario and Luigi in the water. The Mario Bros. can perform the Spin Jump on them to "ride" them, or use Yoshi. They appear in three levels: the third secret level on top of the Vanilla Dome, a secret area in the Cookie Mountain level, and a hidden area within Chocolate Island 1. Unlike the Floating Mines, they are vulnerable to Fireballs.

New Super Mario Bros. Wii
After a long hiatus, Porcupuffers are featured again in New Super Mario Bros. Wii. Here, they attack exactly the same as the Spike Bass in the predecessor, swimming near the surface to pursue the plumber and his party or even leaping from the water to attack. Porcupuffers serve as obstacles for World 4, and they appear again in World 6 in level 6-5 and later in World 9 in level 9-2. They can only be defeated with a fireball, star or Koopa Shell; another one will come to take its place several seconds later. This also occurs in the Enemy Courses, although the replacement occurs much quicker. They can also be frozen, but they crack out almost instantly, much like a Spiny Cheep Cheep.

Super Mario Galaxy 2
Although Porcupuffers don't appear in Super Mario Galaxy 2, the lone Spiny Cheep Cheep is mislabeled as a Porcupuffer by the game's Prima guide.

Super Mario 3D Land
Porcupuffers later appear in Super Mario 3D Land, inhabiting underwater and beach levels. They retain their appearance from New Super Mario Bros. Wii. In this game, Porcupuffers swim back and forth while underwater, while in World 6-1, they jump out of the water in specific locations attempting to hurt Mario, and may even break some portions of the bridge he uses to reach the end of the level. Aside from the bridge-breaking, these behaviors are shared by this game's Cheep Cheeps.

New Super Mario Bros. 2
Porcupuffers reappear in New Super Mario Bros. 2, acting the same as they did in New Super Mario Bros. Wii. Here, they appear in and. They also appear in stage one of the Impossible Pack downloadable content.

New Super Mario Bros. U
Porcupuffers once again appear in New Super Mario Bros. U, behaving the same way as in its predecessors. They only appear in Porcupuffer Falls in Rock-Candy Mines.

In New Super Luigi U, they appear in Porcupuffer Cavern in Rock-Candy Mines.

Super Mario 3D World
Porcupuffers return in Super Mario 3D World. They behave the same way they do in Super Mario 3D Land. They only appear in Pipeline Lagoon.

Mario Kart Arcade GP
In Mario Kart Arcade GP, an item known as a Needle Bomb appears, which resembles a Porcupuffer.

Mario Kart Arcade GP DX
In Mario Kart Arcade GP DX, they appear as an item that can be placed on the course. They can come singularly, or in a group of three as an item dubbed "Triple Porcupuffer".

Mario & Sonic at the London 2012 Olympic Games
Porcupuffers also appear in Mario & Sonic at the London 2012 Olympic Games. During the Dream Rafting event, the second task a team is required to do is defeat some Porcupuffers. To defeat these Porcupuffers, the participants must Ground Pound the raft at the same time when they're beneath it. They also appear during the Highway Tally game in London Party mode.

Mario + Rabbids Kingdom Battle
In Mario + Rabbids Kingdom Battle, four Porcupuffers makes cameo appearances as fountain statues in Gallery mode.

Trivia

 * The Cheep Chomp is incorrectly referred to as a Porcupuffer in the New Super Mario Bros. Wii Prima Guide.
 * In Minecraft, the Super Mario Mash-Up Pack replaces the skins of the Elder Guardians to skins of Porcupuffers, as well as replacing Pufferfish.