Peace Frog is the 61a and semi-final episode of the final season.
The Bean Scouts have gone into Prickly Pines so that they can each pick out a frog for the Annual Prickly Pines Frog Jump-a-thon.
Lumpus doesn't want to wait around for them, so Slinkman suggests that he take some money and get the frogs some lettuce for them to eat. But in the check-out line, a cowboy pig and a hill-billy stork hassle Lumpus when they seem him buying lettuce and they call him a herbivore. Lumpus is steamed to see them acting all tough while they drive around in a souped up truck. So Lumpus storms out, determined to prove himself as a man among men.
He comes back to Camp Kidney dressed in manly clothes, and driving a huge truck around! Although the Bean Scouts are trying to train their frogs, they are unable to do so due to Scoutmaster Lumpus' constant driving. And the driving is having an adverse effect on the frogs' health. They are getting sick and can't jump like they should be able to jump.
Lazlo, not wanting the frogs to be unwell, suggests to Scoutmaster Lumpus that if Lumpus can stop driving his truck around for a week, Lazlo will let Lumpus race Lazlo's pet frog, Frederick, in the Prickly Pine competition. And if Frederick wins, Lumpus can win and keep the manly trophy all for himself! Lumpus agrees to this deal, but has a hard time making it through without driving his truck.
He's weak, and has to roll around in a wheel-chair. But then Frederick hops up into Lumpus' lap and licks his nose! When Lumpus sees the frog up close, he starts to change his mind and thinks that maybe the frog isn't so bad after all. But then Frederick starts to hop away and Lumpus has to chase after it.
Lumpus is inconvenienced when he falls off a cliff and hits himself on the rocks, but then he sees where the frog has taken him. It is a beautiful, remote lake. Enthralled by the splendor of nature, Lumpus begins to enjoy doing the stuff that Frederick does. So when the time comes for the competition to come around, Lumpus is nervous and apprehensive about having the frogs compete. But when Slinkman drives Lumpus' truck to the event, the exhaust from the truck's fumes is causing the frogs to hack and cough.
Lumpus realizes that having the frogs caged and helpless to do anything is wrong, so he frees all the frogs, and decides that he doesn't need a truck or a trophy to prove who he is, he's happy just the way he is.
The name of the adult pig who wears a cowboy hat and can usually be seen around in Prickly Pines, is revealed to be Beaufort.
End Credits: Scoutmaster Lumpus' key for his truck falls into the house of a fish family in Leaky Lake, and a male fish thinks that it's a sign of male superiority.