Timed Thwomp

Timed Thwomps are a sub-species of Thwomp that have timers as a nose. When their timer goes off, they fall down.

Super Mario Adventure
Timed Thwomps make their first appearence in Super Mario Adventure. They are only seen in a few levels. They are also seen in Larry Koopa's second boss battle, where Kamek creates three on the ceiling.