Mosshead has short moss green hair, brown eyes and has two long teeth showing. He wears a black shirt with red/white striped sleeves with bones in X-shape printed, purple shorts, white sock with a red stripe and lime green sock as his odd socks; and brown shoes laced.
He appears as a background character, but mostly as one of Thatch's gang members. He looks tough, but is annoying (as known in episode 'Messy Business at the Manor'). He also praise Thatch...always.
He can spit moss (hence his name) and when it hits a particular target (like a chair or food), the target rots into green ash-like bits.
Typically, he doesn't show relationships among others. Although, he has a pet cane toad named Ricardo (appears in 'Messy Business at the Manor' and 'The Day the Professor Croaked') and he's one of the members of Thatch's gang.