Spiny Cheep Cheep

Spiny Cheep-Cheeps are blue Cheep-Cheeps with spikes running down their backs. They only appear in one level, 7-4 in Super Mario Bros. 3. Spiny Cheep-Cheeps swim faster than normal Cheep-Cheeps. The spikes don't really make it more dangerous, since Mario and Luigi can't stomp on enemies underwater anyway.

Spiny Cheep-Cheeps also appear in the Super Mario World television series in the "Fire Sale" episode. Yoshi refers to them as Porcupine Fish, as they pop out of the water and paralyze anyone who touches them. In the episode, Mario, Luigi, Princess Toadstool, and Kootie Pie are paralyzed by the Porcupine Fish.

They reappear in Super Mario Land 2: 6 Golden Coins. This small variety was colored black and acted similar to its Super Mario Bros. 3 counterpart.

In the game New Super Mario Bros. Wii, Spiny Cheep-Cheeps are purple. They first appear in World 1-4 and later appear in world 4-1 and 4-4. Once it catches sight of Mario, Luigi, or the Toads, it will hunt them down. Though small, the Spiny Cheep-Cheep is quite fast and relentless in its chase; more so than the Deep-Cheep. They can be frozen by Ice or Penguin Mario, but like all spiked enemies in the game, they will not stay frozen for long.

Spiny Cheep-Cheeps can be defeated if the user has a power-up such as Hammer Mario, Fire Mario, or Invincible Mario.

Trivia

 * A very similar fish appears in Yoshi Touch & Go, as it is blue and spiky, but this unnamed fish's spikes are white, and the fish is always jumping. They can only be defeated by smacking them with an egg. It is most likely a variant of Flopsy Fish.
 * Also, interestingly, in New Super Mario Bros. Wii, if Mario and co. freeze a Spiny Cheep-Cheep, once it unfreezes, it will have an angrier look on its face. This does not affect anything it does.