WordNet sense 1 (a person with an unusual or odd personality):

flake, geek, oddball, eccentric person

WordNet sense 2 (a person of a specified kind (usually with many eccentricities)):

case, character, type, case

WordNet sense 3 (conspicuously or grossly unconventional or unusual):

bizarre, flaky, freakish, freaky, off-the-wall, outlandish, outre, flakey, gonzo

WordNet sense 4 (not conventional or conformist):

unconventional

WordNet sense 5 (not having a common center; not concentric):

nonconcentric