nuts
bats
nut-bar
kee siao
fruity
crazy as a bedbug
siao
distraught
cracky
daft
mad as a box of frogs
three stops short of Dagenham
toppy
unglued
bonkers
batty
funny in the head
out of one's mind
crackers
bughouse
nutso
bananas
hatstand
bugfuck
berko
gobaloon
not right in the head
meshuggener
plumb crazy
nutzoid
gone fishing
loony
insano
potty
deranged
doolally tap
loony tunes
insane in the membrane
crazy as a cootie
mad as a March hare
crazy as a cootie bug
gila
one fry short of a Happy Meal
cracked as an egg
wud
becrazed
nutty
lunatical
demented
not wise