Pronounced "Hoo-Dem-Iya", phrase coined by Florida Natives "The Black Project". Variations of it include Who U Iz and Who I Iz. Can be used also as Who Dat and Who Dis. Used to address someone you do not know.
Ajay: Hey, Kareem.
Kareem: Who dem iz?
Jay: I don't know.
Salem: I was talkin' to Sarah last night.
Jack: Who dem iz?