Spiny Cheep Cheep

Spiny Cheep-Cheeps are blue Cheep-Cheeps with spikes running down their backs. They only appear in one level, 7-4 on Super Mario Bros. 3 but 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.

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

A very similar fish appears in Yoshi Touch & Go, as it was blue and spiky, but this unnamed fish's spikes were white, and were always seen jumping. They could only be defeated by smacking them with an egg, and is actually most likely a spiky variant of Flopsy Fish.