Stumpy is playing with a hairdryer, pretending that it is a weapon and he is Mr. Coolskin, fighting a dinosaur (he's really just blowing the hairdryer at a sheep). Kaeloo explains that dinosaurs only existed in prehistoric times, and as Stumpy keeps annoying her, the frustrated frog pushes him into a ditch. Stumpy finds a bone inside, which turns out to be a prehistoric fossil. Quack Quack examines the bone and notes that it has been a long time since anyone saw Mr. Cat, and Kaeloo realizes, with horror, that he is trapped in prehistoric times, due to the events of the previous episode. The trio decide to rescue their friend, and they use the time-travel car from the previous episode to travel to prehistoric times.
Mr. Cat is searching for a way to get back to the present when he comes across an annoying prehistoric version of himself, who keeps chewing on his (Mr. Cat's) tail.
The other three arrive using the car, and Kaeloo is excited upon seeing all the prehistoric objects along the way (despite having most of the exact same things in the present). Stumpy meets a prehistoric version of himself, who is just as crazy as him if not more so. Quack Quack, meanwhile, tries to defend a herd of giant yogurts with large horns (who are capable of movement) from a prehistoric version of himself, who hunts them.
Mr. Cat, after escaping from Prehistoric Bad Kaeloo, finds the car and rejoices, but his joy is short-lived as Prehistoric Mr. Cat chews on one of the car's wires, damaging it.
Prehistoric Stumpy expresses an interest in Present Stumpy's game console (after the latter loses as usual), and Present Stumpy lets him see it. Prehistoric Stumpy stamps on the console and wins the game, and both of them continue stamping on it to win the game.
Present Kaeloo searches for Mr. Cat and finds Prehistoric Bad Kaeloo, and starts making notes on her physical appearance, angering her and causing her to punch Present Kaeloo. Present Bad Kaeloo roars at Prehistoric Bad Kaeloo, causing her to transform into Prehistoric Kaeloo and start crying. Present Bad Kaeloo transforms back to normal and expresses remorse for her actions.
Present Mr. Cat is still fixing the car, and Prehistoric Mr. Cat keeps biting the wires, causing Mr. Cat to beat him up.
Prehistoric Stumpy gives Present Stumpy a bow and arrow and tells him to hunt the yogurts. Stumpy tries, but fails, launching the arrow straight into the ground. However, he does manage to attract the attention of the herd of yogurts, who turn to face him. Prehistoric Stumpy sneaks away, and Present Stumpy and Quack Quack run for their lives.
Present Kaeloo is psychologically assessing Prehistoric Bad Kaeloo when Stumpy yells at her to run, since the stampede is heading that way. Kaeloo, Stumpy and Quack Quack continue running when Mr. Cat shows up in the car, which he managed to fix, and saves them. Kaeloo expresses joy in the fact that he is still alive.
Mr. Cat drives the car at an increasing speed, and the car heads towards an abyss with the yogurts in hot pursuit. The car and the yogurts go over the edge of the abyss, but fortunately the car reaches 88 mph (the speed needed for it to fly) just in time, and the four friends return back to the present. Stumpy continues pretending to fight dinosaurs, and Kaeloo reminds him that dinosaurs only existed in prehistoric times, but the buddies' interference with the past has apparently rendered that statement false - a giant dinosaur walks right past them. The episode ends as the four of them stare in horror at the giant dinosaur footprint on the ground.
- Mr. Cat
- Prehistoric Stumpy
- Quack Quack
- Prehistoric Kaeloo
- Prehistoric Mr. Cat
- Prehistoric Quack Quack
- This episode, along with the previous one, is the series' first two part episode.
- At the beginning of the episode, Kaeloo mimics the Terminator before driving the car.
- This episode and the previous one are parodies of Back to the Future.