Didn't Think This Through: Doofengung's evil plan has him poking a mammoth with a sharp stick so its herd will stampede into his brother's territory. However, when he tries it, the mammoth simply turns around and sees that Doof is the one who poked it and the herd stampedes after him instead.
The Discovery of Fire: Can-tok accidentally discovers fire when her spear is ignited after she drops the end of it in some molten lava.
Elseworld: Transplants the standard P&F formula into the prehistoric era.
Framing Device: Throughout the episode, we shift to creators Dan Povenmire and Jeff "Swampy" Marsh in low-budget photo animation discussing the episode to explain something going on.
Freudian Excuse: Apparently, Doofengung's Devonian fish ancestor decided to bail out on the journey onto dry land, hence why he is less evolved than his brother.
Handsome Heroic Caveman: Doofengung's brother is a straight-backed, muscular, clean-shaven caveman, opposed to the more hunched, skinnier, scruffier Doofengung.
Race Lift: Or species lift in this case. Carl the Intern becomes a hyperactive monkey named Gnarl.
Reality Has No Subtitles: With a few exceptions, most of the dialogue is told in "cave talk" gibberish. But the formula should be familiar enough to fans to understand what's going on.
Strictly Formula: This episode exploits the show's use of this trope. Even though almost the entirety of the episode has the characters as completely unintelligible cave people, it's still very easy to tell what's being said based on the show's plot structure and very common Running Gags.
Surprisingly Realistic Outcome: Doofengung tries to drive his brother out of his territory by poking a mammoth with a stick and causing a stampede. Poking a mammoth with a stick causes them to chase him instead.