WordNet sense 1 (changeable):

capricious

WordNet sense 2 (not capable of being foretold):

unpredictable

WordNet sense 3 (not normal; not typical or usual or regular or conforming to a norm):

abnormal

WordNet sense 4 (conspicuously or grossly unconventional or unusual):

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

WordNet sense 5 (not conventional or conformist):

unconventional