A Spiny Cheep-Cheep (also spelt as Spiny Cheep Cheep) is a enemy in the Yoshi series debuting in New Super Mario Bros. Wii it is a fish that is surrounded by spikes they originally debuted in Super Mario Bros 3. They are a sub-species of Cheep-Cheep. A similar species to them called the Spiny Fish also appeared in Yoshi's Story.
New Super Mario Bros. Wii
Spiny Cheep-Cheeps appear in New Super Mario Bros. Wii as common enemies underwater. They attack by chasing after Mario whenever they see him. Unlike the Deep-Cheep, the Spiny Cheep-Cheep relentlessly chases Mario and doesn't stop. They can be a nuisance (especially when heaps come at you) and they are usually found in underwater sections. To defeat them, you will need to shoot fireballs or use a Starman. Iceballs will only freeze them for a few seconds before they break free and aggressively chase you thereafter. Tagging a Checkpoint will cause any Spiny Cheep-Cheeps chasing you to retreat.
New Super Mario Bros. U
Spiny Cheep-Cheeps return in New Super Mario Bros. U, in this game, they are slightly more common and behave as they did in the previous game, just as before, they chase the heroes upon sight and can be defeated in the same ways as before (with the effects of a Fire Flower or Starman). And just as before, tagging a Checkpoint will cause all the Spiny Cheep-Cheeps chasing you to retreat. In this game, they can also be destroyed by Cheep Chomps.