Now that 'Family Guy' creator and lead voice Seth MacFarlane has hopped universes to lend a voice to 'The Simpsons,' let it never be said that the animation titans can't have a friendly back and forth. Former 'Simpsons' writer and late-night legend Conan O'Brien will lend his voice to an upcoming episode of 'Family Guy,' but as whom?

'Family Guy' seems to have gotten to almost every celebrity in its 14 years on the air, but the upcoming twelfth season has only just gotten to Conan O'Brien. Via Entertainment Weekly, we've learned the 'Conan' host and former 'Simpsons' writer will appear as himself this fall.

The season 12 episode in question will see Peter and Quagmire forming a singing duo appropriately called "Griffin and Quagmire," after their mutual fright from a bee leads them to scream in perfect harmony and discover their talent. The two then play a music festival and wind up performing on 'Conan,' which predictably goes awry.

Also on deck for the twelfth season of FOX's Animation Domination lead are 'Downton Abbey' star Michelle Dockery, Bill Maher and 'The Newsroom' star Jeff Daniels, while season 11 featured the likes of Jessica Biel, Sofia Vergara, Ryan Reynolds, Johnny Depp, Elizabeth Banks and Kellan Lutz.

What say you? Will you tune in for another animated worlds collision when Conan O'Brien comes to 'Family Guy'?