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.