Maverick(n.) An independent person who refuses to be subjected to rules or norms; originally, a cattle owner who neglected to brand his cattle.
Thesaurus Entries
Bohemian, Brahman, Indian buffalo, agitator, alien, ass, aurochs, beat, beatnik, beef, beef cattle, beeves, bigot, bison, bitter-ender, bossy, bovine, bovine animal, brawler, breakaway, buffalo, bull, bullethead, bullock, calf, carabao, case, cattle, character, cow, crackpot, crank, critter, dairy cattle, dairy cow, deviant, diehard, dissenter, dogie, dogmatist, donkey, dropout, eccentric, extremist, fanatic, far out, flower child, freak, free and easy, fringy, frondeur, hardnose, heifer, heretic, heretical, hermit, heterodox, hippie, hobo, hornless cow, informal, insubordinate, insurgent, insurrectionary, insurrectionist, insurrecto, intransigeant, intransigent, kine, kinky, kook, last-ditcher, leppy, lone wolf, loner, malcontent, meshuggenah, milch cow, milcher, milk cow, milker, misfit, mule, muley cow, muley head, musk-ox, mutineer, natural, neat, nonconformist, nonjuror, not cricket, not done, not kosher, nut, odd fellow, oddball, oddity, offbeat, original, outsider, ox, oxen, pariah, perverse fool, pighead, positivist, purist, queer duck, queer fish, queer specimen, rara avis, rebel, revolter, revolutionary, revolutionist, rioter, screwball, sectarian, sectary, solitary, standpat, standpatter, steer, stickler, stirk, stot, subversive, swinger, traitor, tramp, type, ugly duckling, unconformist, unconventional, unfashionable, unorthodox, way out, wisent, yak, yearling, yippie, zealot, zebu