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. They come in two colors: pink with red spots and yellow with blue spots. On ceilings, pink Sluggies remain stationary, while yellow 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

 * Official Nintendo 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.)