nutsy
crazypants
gaga
banoodles
loco
buggish
wiggy
cray
cray-cray
jiggy
loced out
bammy
bananapants
crazy-ass
nerts
crazyish
half-cracked
crazy as a shithouse rat
get one's freak on
like nobody's business
not right in the head
meshuggener
mad as a March hare
flooey
nutso
nutzoid
crazily
off the beam
off one's rocker
off one's onion
bugnuts
gone fishing
not have both oars in the water
jimjam
hatstand
insane in the membrane
crackers
loony tunes
bughouse
go potty
off one's chump
becraze
off one's head
out of one's mind
lose one's mind
go ham
becrazed
cuckoo
bananas
dumb out