Ur, what?! Will Ferrell appeared on The Tonight Show Starring Jimmy Fallon on Wednesday, March 18, to promote his new movie Get Hard. But for some unknown reason the comic actor decided to make an appearance dressed as Little Debbie, of Little Debbie's snack cakes — and he didn't break character for one second!

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Evidently confused at his guest's choice of attire (a blue plaid dress and matching straw hat), Fallon asked Ferrell what the little girl costume was all about.

"Well I have to wear it," he explained. "I am the new face of Little Debbie snack cakes. I'm not the Hollywood hunk I once was, this mug ain't making the moolah like it used to. I've got a mouth to feed, mine," he answered before adopting a little girl's voice and taking every opportunity to promote his range of confections.

Reduced to baffled giggles, Fallon sat by while Ferrell spoke directly to the audience, informing them that by being at the show taping that night, they all have the "opportunity to go out and buy a packet of Little Debbie snack cakes!”

When Fallon attempted to interview Ferrell about his new movie, the comedian refused. "Please call me Little Debbie," he insisted, before proving his skills as a Little Debbie connoisseur, by being able to tell the difference between a baked potato, and a snack cake.

Later, as Fallon declined Ferrell's offer to read a promo, Ferrell took his impersonation to the next level. "I'm just a wittle girl, won't you just wead it for me?" he pleaded, batting his eyelids.

Of course, when Fallon agrees, the results are pretty hilarious! Watch the whole, totally bizarre but awesomely funny interview in the video above.