From the Super Mario Wiki
Micro Bombs are subspecies of Bob-ombs and are very small. They are thrown by Punchinello in Super Mario RPG: Legend of the Seven Stars. They are the first to be thrown, and the weakest, but they can still be a problem if they are left alone. Soon after they are defeated, more are thrown, but when Punchinello loses enough HP, they stop being thrown and are replaced by regular Bob-ombs.
- The Micro Bomb's Psychopath thought is a reference to the 1994 film Forrest Gump, in which the titular character's catchphrase is "stupid is as stupid does".