Watch out, Bruno Mars! Four-year-old Kai rocks a fedora just as well as the 'Locked Out of Heaven' singer, who performed 'Grenade' on 'Ellen.'

Kai emotes like a pro, closing his eyes, raising his arms and uh, ad libbing a lot of Mars' lyrics to 'Grenade.' Mars loved Kai's performances so much that he arranged for DeGeneres to give him and his family VIP passes to one of his concerts. We're crossing our fingers for an onstage duet!