Upon reading a few more lines on the definition I think I was point on Kirin:
jackass
noun
One deficient in judgment and good sense: ass, fool, idiot, imbecile, mooncalf, moron, nincompoop, ninny, nitwit, simple, simpleton, softhead, tomfool. Informal dope, gander, goose. Slang cretin, ding-dong, dip, goof, jerk, nerd, schmo, schmuck, turkey. See ability/inability.
Synonyms: bozo, cuckoo, fathead, goof, goofball, twat, zany, goose
In fact I would think I picked one of the nicest versions.