admittedly, about to go to bed and too lazy to check if any of these are taken, but if I don't do this now I'll forget completely.

ominouscookie
donotmockcookie
listenstocookies
cookiewhisperer
noquestions (do not question uncle!)
thirdperson / 3rdperson (because he speaks in third person?)
chiomatic (i remember an episode with a chi-o-matic)
goodchi
driedsalamander
driedpufferfish
equiplizard
magicwaffleiron (uncle's description of jade's laptop)
olddog (Uncle was born in the year of the dog)