Treasure Pest

A Treasure Pest is an enemy in Wario: Master of Disguise. It makes its first appearance in the Smithsnorian Museum and appears in all locations following it. From afar, they look exactly like a Treasure Chest, but when Wario comes near it grows a big eye and attacks Wario. Their names are based on "Treasure Chest".

Treasure Pests randomly replace one red treasure chest (that is, one that does not contain a level-specific item such as a key, or that level's map) at the start of the level, preventing the player from winning that treasure; Wario will have to return to this level later in order to get the treasure the Pest swallowed up.

In-game Description
''A devious mechanical trap made to look like a treasure chest. It yearns to put a hurtin' on all who draw near to steal the sweetness within.''