In his human form, Chopper has blonde hair, dark eyes, and a calm face when happy. He wears sweats and a work-out shirt. As a wrestler, he keeps a towel with him at all times to wipe off sweat. When he is angered or excited, his face becomes ghastly with rage. In his troll form, his shirt rips off due to the increase in his body mass, his teeth become sharper and spikes run through his hair.
Chopper is shown to be "all brawn and no brains", wanting to prove himself the strongest and is willing to fight anyone that he deems to as tough as Kuyo or anyone strong.
Chopper is first seen in the locker room hearing about a rumor by some of the girls about how Tsukune Aono is the toughest guy in the school because he defeated Kuyo. He protest on this believing that he's the toughest. He goes on the search to find Tsukune in the boy's bathroom to fight him to see who's the toughest guy in school but is haulted by Ginei Morioka. Chopper eventually finds Tsukune once more on the roof outside and takes this time to fight him has he transforms. Moka Akashiya tries to intervene but is caught by Chopper and Tsukune tries to jump in to save her but is shoved off. Moka injects her blood into Tsukune as he transforms in his temporary vampire state. Tsukune defeats Chopper by throwing him. Chopper clearly underastimated Tsukune believing that Tsukune is tougher than him.