The hit animated series "Transformers Prime" is about to segue into it's three-part finale next Saturday and it turns out a legendary character from the series mythology is finally making his "prime" debut: Unicron.

HitFix can exclusively reveal that for the first time since none other than Orson Welles voiced the legendary character (in what turned out to be the final performance of his life), Unicron will take on both the Autobots and the Decepticons in the Season Finale of "Transformers Prime" on Sat. Oct. 1 at 8:30 PM.

A preview for the season finale airs tomorrow night and HitFix has the exclusive first look embedded in this post.  You know it's getting serious when Optimus Prime yells "Unicron!"

The last time Unicron was seen by Transformers fans was in the 1986 animated movie. The gigantic robot is known to transform into a planet and has evolved in the mythos of the franchise into a god of chaos.  How will he affect the fate of everyone's favorite alien robot race this time around?  We're guessing cliffhanger, how about you?

You can also check out an exclusive tease of Unicron in the image below.

"Transformers Prime" airs Saturday nights on The Hub at 8:30 PM.

Unicron appears on the season finale of TRANSFORMERS PRIME