Tap-Tap

Tap-Taps are small spike covered enemies that walk back and forth in Super Mario World 2: Yoshi's Island. The silver ones walk off platforms unlike the pink ones. Sometimes they'll hop up and down. They can't be hurt in any normal way, except for an egg. A quick egg will send one flying backwards, and if it hits another, the other one will be destroyed.

Tap-Taps have also appeared in Yoshi Topsy-Turvy, Yoshi Touch and Go and Yoshi's Island DS, where they behaved similarly.

Notable Tap-Taps

 * Tap-Tap the Red Nose
 * Tap-Tap the Golden

Trivia
Spiky Tromps and Spiny Tromps look very much like Tap-Taps, they are also round and covered in spikes.