Sluggy

Sluggies are hairy slug-like creatures found in Super Mario World 2: Yoshi's Island and its remake Yoshi's Island: Super Mario Advance 3. Their spots come in two colors: red and blue. On ceilings, red Sluggies remain stationary, while blue ones slowly move about. Sluggies can fall on Yoshi from the ceilings, and crawl on the ground when they land. Sluggy the Unshaven is the boss form of a Sluggy. The only place they appear in is Sluggy The Unshaven's Fort. They can be defeated by jumping on them. They reappear in Yoshi's New Island in Ready, Steady, Go!. In this game, they only come in red.

Super Mario World 2: Yoshi's Island

 * Shogakukan guide: 気の弱そうなナメクジの一種. 天井からポタポタ落ちてくる. (A kind of feeble-looking slug-like creature. They flop down from the ceiling.)
 * Player's Guide: You always have a few seconds before this ceiling-crawler falls onto Yoshi's head.

Yoshi's Island: Super Mario Advance 3

 * Shogakukan guide: 気の弱そうな、ナメクジの一種. 天井からポタポタ落ちてくる. (A kind of feeble-looking, slug-like creature. They flop down from the ceiling.)

Yoshi's New Island

 * Shogakukan guide: 天井や地面をゆっくりとはっており、近づくと天井から下に落ちてくる. 天井が高いと舌が届かないので、地面に落ちてきたところを食べてタマゴにしよう. (They slowly crawl on the ceiling and ground, and when you approach them, they fall down from the ceiling. If the ceiling is high, you cannot reach them with your tongue, so eat them when they land on the ground for eggs.)