who dat is 

term used by elementary school dropouts to ask "who is that"

have you met larry?
who dat is?

who dat is by max powers March 22, 2003

Who dat boy? Who him is?

A question science cannot answer.

Yo, Who dat boy? Who him is? Him that nigguh, I swear.

Who dat boy? Who him is? by notatrick June 12, 2021

whodatis 

An inquisitive approach of "who is that?" "who are you" or some such similar question.

Whodatis? That's just my baby daddy.

whodatis by La Fawn Davis June 30, 2003