Beep is the name given to a giant Monty Mole with a Rocky Wrench atop its head. In Super Mario Maker, it serves as the boss of the Monty Mole's Burrow (9AC1-0000-0051-5A63-CD63) and BeepBooBooBaaBaaWigglyPeepBowserJr. (EAD1-0000-00AA-071A) levels.
Beep serves as the main boss of the Monty Mole's Burrow level, where he is fought at the end on a wooden bridge. Later, he makes appearance as the first boss of the boss rush level BeepBooBooBaaBaaWigglyPeepBowserJr.. In the latter level, he must be let out of his cage using a P-Switch.
The Rocky Wrench
Legend has it that the Rocky Wrench was stuck to his head after Beep was digging underground and the force was so strong that it sucked the Rocky Wrench onto the Beep's head and was stuck there forever.
Beep seems to be somewhat selfish, though because of his cute looks, often gets what he wants.