Mammoth is a metahuman who possess super strength and a member of the H.I.V.E. Five. Due to his size and strength, he is often singled out by Robin as his opponent.
When Beast Boy chose to remain in his gorilla form, the other Titans advised Robin to pretend as if it didn't bother him. The two were confronted by Mammoth in front of Justice Java, but Robin, having grown frustrated with Beast Boy, dropped his staff and remained motionless, allowing the giant to crush him.
Teen Titans Go! comic book series
Mammoth robbed a bank in Downtown Jump City and was presumably defeated by the Teen Titans.