Ghostfreaked Out

Plot
A boy throws a frisbee and it gets stuck in a tree. The boy climbs the tree to get it, but can't come down. Ben and Gwen show up and see this, Ben becomes Wildmutt to climb the tree and get the boy. Wildmutt talks just like Ben and tries to reassure the boy, the boy turns around and has Ghostfreak's eye and in Ghostfreak's voice he says he wants to be let out. The whole setting changes to a giant Ghostfreak and giant Ghostfreak tells Wildmutt to let him out. Ben suddenly wakes up and falls out of bed. The whole thing was a nightmare.

Ben begins having strange feelings about Ghostfreak, as Max drives Gwen to a school she wishes to attend, Bancroft Academy. Ben callously calls the school a "school for snobs and posers". Upon arriving at the school, they are given a tour by a snobby student named Tiffany. During the tour, Ben begins to see strange things, such as Ghostfreak's shadow and Ghostfreak's eye in a beaker telling Ben to let out him out. Ben's behavior is making Tiffany start to think Gwen isn't Bancroft material and Gwen was about to punch Ben until they hear a noise coming from the gym. It's the Circus Freaks and they have come to rob the school.

Ben arrives and the Circus Freaks recognize him. Ben tries to become Heatblast, but becomes Ghostfreak. But when Ghostfreak battles the Circus Freaks, Gwen and Max notice Ghostfreak is fighting very viciously and not the way he fights his enemies at all and he even scares Gwen in a strange manner. The Circus Freaks escape and Ghostfreak chases them.

The Omnitrix times out and Ghostfreak reverts to Ben, but Ben realizes Ghostfreak has escaped the Omnitrix, really called Zs'Skayr. Zs'Skayr explains to Ben that he has entered the Omnitrix to possess Ben in order to take over the world and has been freed from the Omnitrix this whole time. Zs'Skayr removes his second layer of skin, revealing his true form. However, Zs'Skayr has now developed a new weakness; his body cannot resist light. Ben escapes from Zs'Skayr's clutches. Zs'Skayr then possesses a Bancroft boy playing a tuba and realizes he can't be destroyed by sunlight when he's a host body. Zs'Skayr finds the Circus Freaks hiding in a shed and makes them his minions by possessing Thumbskull and throwing him around. Ben tells Gwen and Max about Ghostfreak escaping and then they begin searching the school for him.

At night, Ben notices some Bencroft students running away screaming and becomes Four Arms to see what's going on. The Circus Freaks come out and Zs'Skayr has possessed Acid Breath. He leaves Acid Breath and tries to possess Four Arms, but realizes he can't possess Ben in alien form. Zs'Skayr then possesses the Circus Freaks to fight Four Arms, but Four Arms defeats them all. Zs'Skayr then possesses Gwen and fights Four Arms. Gwen Zs'Skayr climbs up a wall and Four Arms follows. But Four Arms reverts to Ben and holds a sungun at Gwen Zs'Skayr, but Zs'Skayr will make Gwen die unless Ben surrenders to him. Ben decides to surrender, and Zs'Skayr leaves Gwen but has the Circus Freaks battle Gwen and Max.

Ben becomes Grey Matter to avoid being possessed by Zs'Skayr and then begins to make the Circus Freaks fight each other. Zs'Skayr chases Grey Matter. Grey Matter soon reverts to Ben and Zs'Skayr has another opportunity to take over Ben. But sunlight approaches and Ben pulls down the curtains. The sunlight that is revealed kills Zs'Skayr. The police come and arrest the Circus Freaks, and Gwen now has no chance of attending Bancroft Academy. Ben cheers her up by saying none of the students would have been able to stop Zs'Skayr or the Circus Freaks, while she could.

Major events

 * Ghostfreak escapes from the Omnitrix and Ben can no longer transform into him.
 * The Circus Freaks return.

Debuts

 * Zs'Skayr

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Max Tennyson
 * Tiffany
 * Students of Bancroft Academy

Villains

 * Zs'Skayr
 * Thumbskull
 * Frightwig
 * Acid Breath

Aliens Used

 * Wildmutt (dream)
 * Ghostfreak (accidental transformation, selected alien was Heatblast)
 * Four Arms
 * Grey Matter

Errors

 * Zs'Skayr had an Omnitrix symbol until he tore off the extra skin.
 * When Wildmutt was being held by Ghostfreak in the dream, his brave was orange.

Trivia

 * This is the first and only time Wildmutt talks in the original series, but it was in a nightmare.
 * When Acid Breath says "I ain't scared of no ghosts!", it's a reference to the Ghostbusters phrase "I ain't afraid of no ghost!".