A few months ago we heard the surprising news that 'The Simpsons' had cast its largest animation rival in 'Family Guy' creator Seth MacFarlane for an upcoming guest stint, to be utilized as this fall's season 25 premiere. Now however, 'Simpsons' producers have instead moved the animation mogul's appearance up to the May 19 season 24 finale, and released the first pictures of MacFarlane's alternate reality turn in Springfield! Take a look for yourself inside!

'The Simpsons' will be getting a visit from one of their biggest rivals sooner than expected, and we don't mean Shelbyville. Originally scheduled to lend his voice to this fall's premiere, 'Family Guy' and FOX animation titan Seth MacFarlane will be heard a bit earlier than intended, as he guest stars in the May 19 'Simpsons' finale "Dangers on a Train."

Via Entertainment Weekly, “Dangers on a Train” will see MacFarlane giving voice to the charming Ben, a married Man whom Marge accidentally connects with when she mistakes an “Ashley Madison” marital affair-type website for a cupcake-cake themed page. Much of the duo's bonding comes from a mutual love of “Upton Rectory,” a ‘Downton Abbey’ of sorts for ‘The Simpsons.’ Comedian Lisa Lampanelli also guests as MacFarlane's character's wife.

“We thought we had a great part that he’d be perfect for, and it would be great to have him on our show, so it worked out just right,” Simpsons executive producer Al Jean said of MacFarlane. “There’s been a little rivalry. We’re both humor shows and we make jokes, but it’s always been friendly.”

EW also obtained the first pictures of MacFarlane's appearance in the May 19, while no explanation was given for the shift from fall to May. What say you? Will you tune in to 'The Simpsons' 24th season finale to see Seth MacFarlane collide with Homer Simpson?