Airdate: May 8, 2011
Written by: Stephen Warbrick, John J. Miller
Story editor: Chris McCulloch
"Ghosts" contains examples of:
- Absentee Actor: The second of three episodes to not have the Twins in any capacity.
- Comically Missing the Point: The Warden refuses to notice any signs of supernatural activity, no matter how blatant- until he winds up dragged through the sewers by the dead.
- Continuity Nod: The Prison Mogul's assistant Gerald is shown as a zombie. The ghost of Cancer also later appears, playing around with Ash.
- In a disputed example, there are fans that believe the ancient society shown at the beginning of the episode may be that of Pummelonia, although it's unconfirmed by the creators if it was meant to be one and the same.
- Freeze-Frame Bonus: The Warden's photo album. Besides the photo he points out of his father yanking his tooth out, there's a photo of a child Warden biting off a puppy's tail, and a photo of a teenage Warden with a mullet hairstyle and a muscular, wall-eyed prom date.
- In the final scene, aside from the Jacknife flower, Lord Stingray can also be seen as one (although his death was not shown on screen). Gary is also depicted as one of the blades of inmate grass.
- Funny Background Event: Jacknife was apparently murdered by the vengeful ghost of his dad, as while the Warden and Chet speak, we see a Jacknife ghost angrily flying after his dad in Limbo and brandishing a knife.
- As the Doctor explains he'll have to temporarily kill the Warden to get him into Limbo, some fairies can be seen flying by and observing- and then freak out and fly off as they're chased by one of the Doctor's experiments, who's using flamethrowers on them.
- Gainax Ending: The Warden and Jared are taken into the afterlife, but are rejected and told "Not yet" by the strange seven-headed deity. However, the inmate population are reborn as insects and foliage in the jail- and are subsequently killed all over again by the Warden, who muses that it's great to be alive.
- Mayincatec: The basis of the ancient temple that once stood where Superjail's volcano is now, along with its priest Quetzalpacatlan (aka "Chet").
- Reincarnation: The entire mind screw ending centers around this. Jacknife and Lord Stingray are depicted reborn in the form of flowers, Chet is a dragonfly, and the other inmates are assorted plants and grass.
- What Could Have Been: It evolved from a pitch idea about Cancer returning as a ghost, but in the final product, she's just a cameo.
- The animatic reel had the ghost version of Cancer depicted as a little more zombie-like and rotting in her cameo with Ash, adding an eerie effect to her appearance. In the finished product, she's simply a Cute Ghost Girl.
- A visual gag in the animatic reel that didn't get used in the actual episode involved Casper the Friendly Ghost being seen among the ghosts.