Blockhopper
From the Super Mario Wiki
This article is about enemy who appeared in New Super Mario Bros.. For information about similar type of enemy from Super Mario Bros. 3, see here.
hopper.
Blockhoppers (also known as Coin Impostor) are robotic enemies encountered in the game New Super Mario Bros.. They are found only on World 2. They disguise themselves as a ? Block, with Brick Blocks on top of them, but once Mario approaches, they reveal their true form. They are actually blue robot-like enemies, and will hop at Mario in cue with the background music. They can be told apart from ? Blocks by the fact that the question mark on them does not move. They are similar to the Pile Driver Micro-Goombas that disguise themselves as blocks from Super Mario Bros. 3. They can be defeated with either a thrown Koopa's shell or a Ground Pound from above. The player will get a coin or an item if they ground pound the ? Block on the Blockhopper.
