The Scooby gang are invited to Metropolis when Caesar's ghost begins apparently haunting the Daily Planet office. While this quickly gets revealed as one of the Prankster's schemes, the relief doesn't last long, given that the Prankster then turns Superman into a monster with Red Kryptonite.
This comic includes examples of the following tropes:
- Animal Superhero: When Jimmy uses his signal watch, hoping to call Supergirl in to fight her mutated cousin, the summons instead attracts Krypto the Superdog. Additionally, the ever-hungry Scooby drinks Lois' power potion while she's putting her suit on, which gives him powers like Krypto's temporarily.
- Body Horror: The Red Kryptonite causes Superman's skin and muscles to bubble as he transforms.
- Continuity Nod: The events of the comic refer back to "A Super-Friend in Need", in which Mystery Incorporated stopped a "Scooby-Doo" Hoax by the Legion of Doom.
- Deadly Delivery: Toyman gives Superman a lead-lined present after being collared. To make sure it isn't a bomb, Supes opens it...and the rays from the Red Kryptonite hit him.
- Follow the Chaos: After Superman is mutated into a monster by Red Kryptonite, Krypto and Scooby track him down by following the trail of holes in buildings that he left.
- Forgot About His Powers: Velma and Jimmy Olsen dress up as gorillas, surprising the mutated Superman into forgetting about his super speed just long enough for Jimmy to catch him with a Red Sun projector, which drains Superman's powers and allows Krypto and the super-powered Scooby to contain him until the red kryptonite that caused the mutation wears off.
- Grievous Harm with a Body:
- Superman throws Mongul into Terra-Man during an early fight.
- Fred, Daphne, and Lois stall Toyman as he comes out of a bank, allowing Shaggy (currently bouncing all over after being thrown off by Super-Monster) to bowl him over.
- Hypocritical Humor: Velma questions Jimmy's Catchphrase, only for him to point out that "Jinkies" isn't any cooler.
- If I Had a Nickel...: After drinking the potion, Shaggy has a mishap with his elasticity powers that results in him being rocketed across the cityscape. According to Jimmy, this has happened to him a lot.
- Instant Fan Club: Jimmy's Silver Age fanclub comes up when he and Velma go to the headquarters to look for something helpful. When Velma questions him having a fanclub, Jimmy asks her if she has one.
- Insufferable Genius: Brainiac and Grax both consider themselves far superior to their fellow supervillains because of their twelfth and twentieth level intellects. It doesn't help them destroy Superman.
- Master of Disguise: Jimmy's talent for disguises comes up when he and Velma find his disguise trunk while looking for a way to help stop Superman. Jimmy mentions that it's been very useful in the past, but he can't see how it would help here. Then he and Velma have a near-simultaneous "Eureka!" Moment that the disguises could be used as a distraction.
- Mythology Gag:
- The opening situation with Perry White accidentally summoning Caesar's spirit also occurred in The Adventures of Superman episode "Great Caesar's Ghost".
- Superman says "Great Krypton!", which has fallen out of usage since the Silver Age.
- Speak of the Devil: The story starts with Perry White apparently summoning Caesar's ghost due to his habit of yelling, "Great Caesar's Ghost!" (itself a reference to an old Superman storyline).
- Stealth Pun: Caesar's ghost asks if anyone wants salad. Presumably, it would be a Caesar salad.
- Super-Hearing: Exaggerated; Superman's ears are keen enough to hear Jimmy's signal while in space.
- Superpowers For A Day: Scooby becomes a super-dog and Shaggy a Rubber Man after they accidentally drink the potions Lois Lane and Jimmy Olsen were planning on using to combat the mutated Superman.
