Hop-Chops

Hop-Chops (formerly singularized Hop-Chop ) are uncommon enemies that appear in Super Mario 3D World, Super Mario 3D World + Bowser's Fury, and Super Mario Maker 2. They are sentient green springboards with a square head, red eyes, and sharp teeth. These enemies usually appear in groups of three or more, and reside in areas where a springboard is required to obtain a collectible, such as a Green Star.

Super Mario 3D World / Super Mario 3D World + Bowser's Fury
Hop-Chops debut in Super Mario 3D World, and are usually found in groups. When players approach a Hop-Chop, it will begin to bounce toward them. Hop-Chops can be defeated by any attack. Some Hop-Chops react slower than others; these ones turn into springboards when defeated, which the player can then carry and use. Usually, one Hop-Chop per group can turn into a springboard. If left as a springboard for too long, it will turn back into a Hop-Chop. This can also happen while it is carried.

Hop-Chops reappear in the game's Nintendo Switch port Super Mario 3D World + Bowser's Fury, where they act the same way as they do in Super Mario 3D World.

Super Mario Maker 2
Hop-Chops reappear as enemies that can be placed in Super Mario Maker 2 stages, exclusively in the Super Mario 3D World style. In this game, they no longer are defeated when jumped on, instead acting like Trampolines initially. When given wings, Hop-Chops jump and then hover above the ground before dropping back down.