Monokid is a child-like robot. However, he also has a very bad mouth and a short temper, and he's considered the hooligan of the group. He is a noisy and vulgar bully. He enjoys rock music and playing his guitar, and occasionally shouts exaggerated high-pitched screams like a rockstar. He appears to be the most unintelligent Monokub. He doesn't pay attention when others are talking and will randomly spout incoherent nonsense, making him the main cause of conversations getting derailed. He occasionally messes up words or says things backward, and loves to shout his catchphrase "Hell yeah!" He usually repeats things a lot whenever he gets excited over something. Monokid is also most violent out of the siblings. Despite his general aggressiveness, he sometimes panics and shouts loudly and fearfully. It is implied that he is secretly insecure.

Monokid has a rough and gruff voice, usually found yelling or being loud in general. It should be in the medium low to low range for a male, yet there are times where it seems like his voice fluctuates, almost like a voice crack.