With the threat of closure looming for any enclosure that is not up to scratch, the zoo's annual inspection day is serious. The animals scrub up to look their best. The penguins are polished, the baboons are buffed and the tigers are tidied.

After overhearing that zoo poo is valuable, gorilla Jurgen is convinced the zoo's poo is being sold behind his back. He calls a poo strike, but when a mystery poo is discovered, the zoo is gripped by a puzzling case of poodunnit.

A mystery illness leaves Topaz the kangaroo without a hop and the vets scratching their heads. When Topaz is taken for treatment, rumours begin to spread around the zoo that it could be a condition that causes kangaroos to lose their ability to hop.

Neil the wimpy lion is under pressure from his mother-in-law to buff up like previous alpha-male lion Maximus. Neil seeks out ways to improve his physique and, mpressed by Jurgen's muscles, he decides to copy the gorilla and go vegetarian.

Hand-reared Yoyo the penguin thinks he is a human. Thanks to his identity crisis, he doesn't fit into either the human or penguin world, and just when it looks like things can't get much worse, all his feathers start falling out.

Mysterious monsters are rumoured to be lurking in Flamingo Lagoon and keeper Pete Smallbones is on a mission to prove to the zoo that the monsters are real. The keepers and animals all think that Pete is making it up, until Sid the seagull mysteriously disappears. Could Pete be telling the truth? Meanwhile, over on gorilla island, Jurgen and the boys are having to deal with an invasion of their own as Komodo rabbits and strangen rodents start appearing in their enclosure.