The Mystery Inc. gang is invited to the production of Daphne's uncle John Maxwell's latest movie, The Ape Man of Forbidden Mountain. The trouble is, the titular Ape Man turns out to be real and nasty and is trying to sabotage the movie.
This episode contains examples of the following tropes:
- Artistic License – Biology: When they find a half-eaten hamburger with claw marks on the sandwiches, Daphne points out that apes don't eat meat—in real life, apes often do eat meat, but typically not hamburgers made from processed beef. However, Daphne could've meant that gorillas don't eat meat—after all, real gorillas do have a (mostly) herbivorous diet.
- Animal Disguise: The Villain of the Week disguises himself as the eponymous, gorilla-like Ape Man.
- Ass in a Lion Skin: The Ape Man disguised as Scooby-Doo for his Mirror Routine.
- Bookcase Passage: Fred disappears through one after Daphne accidentally hits a button to open it while they are in the library set. The same shot is also used in the series opening.
- Brick Joke: The Ape Man wore a Scooby-Doo Latex Perfection mask as part of a Mirror Routine. At the end of the episode, Shaggy is seen wearing the Scooby mask when pranking the rest of the gang."Surprise! It's the Scooby head the Ape Man was wearing!"
- Catchphrase: Besides his usual "Zoinks," at one point Shaggy also says "Zooks!"
- Disproportionate Retribution: Carl attempts to sabotage the film for the horrible atrocity of not getting top billing.
- Early-Installment Weirdness: The Ape Man is not unmasked in the traditional Dramatic Unmask manner. Instead, Shaggy snaps a photo of the culprit putting his mask on, and once the instant photo is developed, the gang discovers that the culprit is Carl the Stuntman.
- Eight Ball Corner Pocket: Shaggy does this when he and Scooby are playing billiards, unaware that the Ape Man is right behind him.
- End-of-Episode Silliness: The prank that Scooby-Doo and Shaggy play on the rest of the gang, sitting in easy chairs focused on a fireplace set with Scooby wearing an Ape Man mask and Shaggy wearing the Scooby-Doo mask that the Ape Man used during the Mirror Routine scene. Daphne's Uncle John (the movie's director) comments, "Now there's real talent."
- Expressive Mask: Besides the Ape Man's mask (as per standard), the Scooby-Doo latex mask he and later Shaggy wear seems somewhat capable of this; when performing the Mirror Routine "Scooby" is giving one of his usual puzzled looks, and then later on gives a typical cross-eyed Scooby grin right before Shaggy tugs it off.
- Four Legs Good, Two Legs Better: True to his name, the Ape Man walks bipedally like a human and never walks on his knuckles like a gorilla would.
- Fright Beside Them: While playing a game of billiards with Scooby, Shaggy feels the back end of his stick poking someone behind him and thinks it's Scooby... only to see that Scooby’s at the opposite side of the table. It’s the Ape Man who’s behind him.
- Instant Wristwatch: When Shaggy claims he just remembered he had a dental appointment, a wristwatch that wasn't on his hand before suddenly appears and is then absent for the rest of the episode.
- Judicial Wig: Shaggy tries one on when he and Scooby-Doo fool around in the costuming trailer..."Give me liberty or give me pizza pie!"
- Killer Gorilla: The Ape Man, of course.
- Knew It All Along: At one point, Shaggy gets "grabbed" by a stuffed Ape Man dummy, and during his scuffle with it, unknowingly breaks it. When Velma tells him it's not real, he answers, "Well, I hope you don't think he had me fooled for a minute. I knew it all the time." Scooby responds by rolling his eyes and saying "Roh brother!"
- Latex Perfection: The Ape Man (a.k.a. Carl the Stuntman) somehow manages to get a latex Scooby-Doo mask, which he wears to do the Mirror Routine on Scooby-Doo at an opening in a bookshelf on a library set. Then near the end, Shaggy apparently finds the Scooby mask and briefly wears it at the end, while Scooby finds a spare Ape Man mask and has fun with that.
- Mirror Routine: The Ape Man combines this with Latex Perfection when performing the gag on Scooby-Doo at the library set, through an opening in a bookshelf. The real Scooby suspects something is phony when he notices his reflection having the Ape Man's body.
- Monster of the Week: Again, the Ape Man.
- Nobody Here but Us Statues: In the cue ball room, Shaggy and Scooby find four animal head trophies, one of which is a familiar-looking ape. As they play cue ball, Scooby does a literal headcount and notices there's only three of them now — the ape head has disappeared. Because that was the Ape Man hiding to ambush them.
- Nutritional Nightmare: Daphne whips up a "Shaggy Snack" as part of bribing Shaggy to be part of the plan to catch the Ape Man alongside Scooby's usual Scooby Snack bribe. Said "Shaggy Snack" consists of a potpie made of pizza crust and filled with chocolate sauce containing anchovies, pepperoni, and cherries. Of course, being the Big Eater he is, Shaggy can't resist.
- Out-of-Character Moment: A couple of times, Scooby-Doo builds up courage to confront the Ape Man and ward him away, albeit only temporarily. The first is during the botched movie shoot when he saves Candy Mint and beats at the Ape Man a bit before knocking him off the cliff, and again later when he barks and snarls at the Ape Man, causing him to backpedal out of the set.
- Polly Wants a Microphone: The Ape Man movie apparently includes a live parrot who says "Stick 'em up! What's the password?" and Velma, Shaggy and Scooby find the parrot at one point during their search for clues.
- Psychopathic Man Child: Carl didn't achieve the role of the lead and instead got the role of stuntman who plays the villain. How does he respond? By going on a homicidal rampage to sabotage the movie and nearly got innocent people killed. Needless to say, his acting career is surely over.
- Rope Bridge: The scene they attempt to shoot at the start of the episode involves starlet Candy Mint standing on such a bridge, to which the Ape Man will jump and stomp on the bridge to try and knock her off. But when the Ape Man instead shakes the bridge hard with his hands, they know something is wrong.
- Shave And A Haircut: When Scooby-Doo hears Carl the Stuntman knocking from inside the trunk he's trapped in inside his trailer, Scooby-Doo knocks the first part of this tune on the lid, and Carl knocks back the "Two bits" part. Shaggy initially thinks it was a "good trick" Scooby pulls off until he figures someone must be inside.
- The So-Called Coward: Even if Scooby-Doo's a Cowardly Lion, he’s still a fully grown Great Dane and can be quite intimidating if angry. So, when he musters up his courage, the Ape Man quickly backpedals when confronted with a snarling, barking 200-pound hound.
- Southern Belle: Candy Mint, the leading lady in the Ape Man film, complete with a Penelope Pitstop-esque way of saying "Help!"
- Suddenly Speaking: When the Ape Man is sent sliding across the room from the Surprise Slide Staircase, he cries out "Help!" in his true voice (Carl the Stuntman's voice) right before crashing into furniture.
- Surprise Slide Staircase: The old mansion set includes one, which comes in handy in capturing the Ape Man near the end.
- Wounded Gazelle Gambit: After attacking Candy in his Ape Man costume at the beginning of the episode, Carl heads back to his trailer and pretends to have been knocked out and locked in his trunk by the actual Ape Man. Though the gang finds it odd that the Ape Man would be smart enough to do that.
