Nipper Plant

A small white Piranha Plant that stays in one place and jumps up at you in Super Mario Bros. 3. A fire breathing Nipper Plant is at the end of world 7-8. Some of them can hop around making your landing harder.

In Super Mario World 2: Yoshi's Island they're easier enemies and have no eyes. They hatch from "eggs", can be stepped on, and don't jump at you. The eggs they hatch from slowly fall to earth and can be swallowed. The only problem with them is they appear in groups.