As April Fools go, this is pretty special. But not as special as Jimmy Kimmel's wife, who gleefully set the whole thing up. She must've enjoyed an inner guffaw when she saw her husband put his retainer in before he headed off to sleepy land. 

There they are, the dead of night, and Molly Kimmel invites in Rihanna and her crew to treat Jimmy to quite an aggressive rendition of 'Bitch Bettah Have My Money' - proving that you can prank and promote at the same time. Seamless. 

John Krasinski and Emily Blunt are pissed they didn't think of this... 

In slightly more rambunctious April fooling, Katie Couric pranked James Corden. OUCH...