Fred Flintstone is unfrozen in the present day and is taken in by Billy.
- Aside Glance: Fred gives one to the camera when Billy doesn’t understand that he’s giving him his name and renames him.
- Bait-and-Switch: Mandy declares that the group needs "a fast set of wheels" to capture the escaped Fred. We cut to the main trio sitting in a monster truck...which promptly pulls away, revealing that they're actually sitting on top of Irwin's bicycle (them being "in" the truck was an illusion).
- Behind the Black: Fred manages to completely destroy Billy's house within the single second that Billy left him alone in the living room.
- Fish out of Temporal Water: Actively discussed to be the case with Fred. It happens again when he and Billy are frozen together until millennia later when humanity has apparently gone extinct and Earth has been taken over by giant aliens.
- Human Popsicle: Turns out that Fred Flintstone was frozen at the end of his own series. Billy thaws him out using Grim's scythe, and much mayhem ensues.
- Hypocritical Humor: Harold comments that Gladys probably won't want "a filthy, disgusting animal" in the house. He's referring to Fred, but the shot shows him looking just as (if not more) filthy and disgusting as the actual caveman.
- Nuclear Family: Butterbean begins demanding Fred start one of these with her now that he’s kidnapped her.
- Shout-Out: Given that Fred Flintstone is the guest star, there are a ton to his home series:
- Fred has a bit of Pokémon Speak and can only say various arrangements of "Yabba-Dabba-Doo." He does seem capable of learning contemporary English (he recognizes that Billy is asking him for his name and replies "Fred") but doesn't use it.
- Upon discovering a record player, Fred grabs a bird outside and uses its beak for the needle, a reference to the Running Gag of animals doing household chores on The Flintstones.
- When Fred kidnaps Miss Butterbean and steals Principal Goodvibes's car, he shoves his feet through the floor and runs along the road, which is how all the vehicles in Bedrock were powered.
- A non-Flintstones example: when the heroes are flying on Irwin's bike, they're briefly silhouetted against the moon, a direct homage to ET The Extraterrestrial. Just in case the audience doesn't get it, Billy says the situation reminds him "of that movie about the extraterrestrial."
- "Shaggy Dog" Story: Fred ends up frozen again, this time in a block of sherbet, so the trio reburies him in the front yard just where they found him. Mandy lampshades this with the remark "What a waste of an episode."
Grim takes Billy and Irwin to Japan to see kaiju battles.
- The Cameo: The Grape Ape had his head shoved into a volcano in a previous battle.
- Control Freak: Mandy is enraged that Grim would dare take the others for an excursion against her orders and immediately goes to retrieve them.
- Evil Is Petty: Mandy gained nothing from going after Grim’s group as they were having their own fun trip, but the fact they defied her and went without her permission personally stung her which is why she becomes hellbent on retaking them.
