bastard, beast, bleeder(British), boor, bounder, bugger, buzzard, cad, chuff, churl, clown, creep, cretin, crud(slang), crumb(slang), cur, dirtbag(slang), dog, fink, heel, hound, jerk, joker, louse, lout, pill, rat, rat fink, reptile, rotter, schmuck(slang), scum, scumbag(slang), scuzzball(slang), skunk, sleaze, sleazebag(slang), sleazeball(slang), slime, slimeball(slang), slob, snake, so-and-so, sod(chiefly British), stinkard, stinker, swine, toad, varmint, vermin

barbarian, brute, caveman, Neanderthal, savageloudmouth, vulgarianlowlife, miscreant, rascal, rogue, roughneck, scab, scamp, scoundrel, villain, wretchbooby, doofus(slang), fool, jackass, nincompoop, ninny, nit(chiefly British), nitwit, nut, schmo(or schmoe, slang)airhead, birdbrain, blockhead, dink(slang), dolt, dope, dork(slang), goon, half-wit, idiot, imbecile, moron, turkeybrat, insolent, nuisance, pest, snipsnob, snoot, snotdweeb(slang), nerd

son of a gun