Mr. Popo is portrayed as thoroughly malevolent, violent, mean-spirited, ruthless, sexist, greedy, psychopathic, masochistic, sadistic, and an overall unpleasant individual, often being known to traumatize and mistreat those who train under him and simple acquaintances alike. He lives on the Lookout with Kami, but is known to be higher than him in social rank despite Kami being God.
Mr. Popo has a "Pecking Order", in which he references to assert his clout and dominance over his trainees.