A 'better' alternative to using the word 'crazy' or 'insane' to someone. Or just a fun way to call someone crazy. Also, 'mentally jolly' can be used. From the Family Guy episode 'The Fat Guy Strangler'.
"Dr, is my brother really insane?"
"Mrs Griffin, we don't use the word 'insane', we prefer the term 'mentally hilarious'"
When a person laughs hard enough they pull both wrists to their chest and open their mouth while rocking back and fourth but stay in their own personal space. Similar to a velocilaughter.
That girl was laughing so hard she was doing the hilariousaurus rex
Mimilarious means being hilarious however in the way a mimi would do it.
Being snarky/sarcastic
and or hyper and childish is the way to go.
Always witty/cunning or sometimes playing ditzy.
There are also the white valley girl moments that come along which sometimes is paired with being sarcastic.
Cat from victorious but more serious
"I'm so hilarious...HILARIOUS HUH LARIOUS... MIMILARIOUS"
^^^ hyper
Then, there is Jade from Victorious
etc etc find sarcastic snarky people "Oh really now? Would you like some frosting on that cake you call your makeup face?"