Georgette Jelly

Georgette Jellies are blobs of goo that move slowly on the ground. They only appear in Sluggy The Unshaven's Fort from Super Mario World 2: Yoshi's Island and its remake Yoshi's Island: Super Mario Advance 3. Georgette Jellies cannot be turned into eggs by a Yoshi, and stepping on them only makes the goo creatures splatter on the walls. After a few seconds, a splattered Georgette Jelly will fall back on the ground and reform. If slurped and spat out, these creatures can be used as makeshift projectiles. The only way it can be defeated is being spat out at a Dangling Ghost.

Super Mario World 2: Yoshi's Island

 * Official Nintendo Player's Guide: You can splatter a Jelly on the walls, but they always spring back for more gooey good times.