Slips and a mongoose named Carl are the best of friends. They play tag together, they both like saying and playing the same kind of jokes with each other and on others, and they really like each other to. But when they go to one of their courses, an educational film is presented and it presents them with a real shock! Not only does Henry Armadillo learn that his natural enemy is a shark, namely Virgil "Bull" Sharkowski; Slips learns that his natural enemy is the mongoose, which Carl is! Suddenly, all the memories of their friendship disappear and transform into absolute hatred for each other! Slips and Carl will stop at nothing until the other is destroyed, and their antics keep unintentionally harming Adam as Adam keeps getting in their line of fire. Meanwhile, Principal Pixiefrog admits a new Harpy Eagle student into Charles Darwin Middle School, unaware that Jake Spidermonkey's natural enemy is the Harpy Eagle! But Adam has no time to worry about Jake's concerns, he wants to put a ceasefire to Carl and Slips' fighting. So Jake and Adam tie up the two former friends up tight and put them into chairs until they agree to be friends again. But something else intervenes. Principal Pixiefrog comes into the room to tell Carl that he will no longer be attending at Charles Darwin as Carl's parents have decided to enroll Carl at a private Mongoose Academy, so Adam decides to let them go. Suddenly, Slips and Carl remember their friendship and are both saddened at this sudden change of events. They both cry and say that they are going to miss each other. And no sooner do Adam and Jake get that situation resolved than does the Harpy Eagle find Jake! But it turns out that the Harpy Eagle didn't want to hurt Jake, he just wanted to play tag with Jake! And Jake is happy and thinks the Harpy Eagle isn't such a bad guy! Adam on the other hand, is just happy that as it turns out, a human in an all animal school doesn't have any natural enemies at all!
- In real life, a Cobra is the natural enemy of the Mongoose. It is also unlikely that a Mongoose and a Python may attack each other.
- In Mr. Mandrill's film, The enemies are as follows: Robin Vs. Worm, Cat Vs. Dog, Shark Vs. Armadillo, Harpy Eagle Vs. Monkey, and Mongoose Vs. Snake.