You can say "Estoy loco(a)".
Bésame el trasero that's how u say you are crazy about me
loco
¿Eres loco?
Me vuelves loco/a.
No estoy loco
Estamos locos
You say, "tortuga loca."
no demente, desquisiado, son others ways to say crazy.
You could say "Sombrero loco".
loco por ella
It is spanish for NUTTY (crazy).
poeta loco