Jeffy is a 21-year-old guy who keeps living with his parents and keeps acting like a child. He's often rude, Misbehaved, Annoying and mostly smart sometimes. He always says vulgar stuff, hates green beans, and plays his cat piano. When he doesn't like something proceeds to break it. He had a traumatic life, which explains why he acts like that. His adoptive dad is Marvin, and his adoptive mother is Rose. Jeffy wears a blue helmet, a diaper outside of his shorts, and pencil in his nose.