You say, "tortuga loca."
you say You resemble a turtle in French like this, Vous ressemblez a une tortue.
To say crazy in French, fou,(f-oo)
"Crazy" and "insane" can both be translated to "fou" in French.
'ma tortue'
Fou (crazy)
You can say "Je ne suis pas fou/folle" in French, which translates to "I am not crazy."
folle de toi
je t'aim
Chat fou.
You can say "folle vieille femme" in French.
un amour fou