Is it true that it is forbidden to say "O crocodile" to a man and "O lizard" to a girl?

Addressing someone with words of disdain and belittling their worth is an act of reviling and cursing, which is forbidden in Islamic law. This is based on the Prophet's (peace be upon him) saying: "The believer is not a slanderer, nor a curser, nor an obscenity utterer, nor a foul-mouthed person." Therefore, it is not permissible for a Muslim to call others by such words.