Porcupuffer

Porcupuffers (called Porcu-Puffers in Super Mario World) are a species of Cheep Cheeps that first debuted in Super Mario World. They resemble gigantic blue-purple Cheep Cheeps with red lips and blue, cyan, and yellow spikes all over their back. Their name is a portmanteau of "porcupine" and "puffer fish".

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.

Super Mario Galaxy
After a long hiatus, this enemy reappears in the game Super Mario Galaxy. However, only one appears in Drip Drop Galaxy, hidden in an underwater chest.

New Super Mario Bros. Wii
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
Porcupuffers reappear in Super Mario Galaxy 2. Like in the predecessor, they are very rare, and will even disappear a short time after being encountered. They only appear once in Cosmic Cove Galaxy.

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 waterfalls, attempting to hurt Mario, and may even break some portions of the bridge he uses to reach the end of the level.

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

Trivia

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