Bob Fossil sets up a highly illegal and shady kangaroo boxing match between the Killeroo and Howard. Howard thinks that by winning the fight he will impress the Head of Reptiles, Mrs Gideon. Vince enlists his uncle, a bare-knuckle fighter with a very strange accent, to help with Howard's training.

All is not well at the Zoo-niverse. Animals are disappearing one by one. Things go from bad to worse when Joey Moose, one of the zookeepers, goes missing. When Mrs Gideon reports that her python is also on the missing list, Howard is determined to save the day. Howard and Vince stumble across Dixon Bainbridge's secret laboratory and the terrible truth behind his ‘experiments' comes to light.

Howard is hell bent on a career as a serious writer in the hope that he'll improve his chances with Mrs Gideon. However, when famous publisher Hamilton Cork arrives at the Zoo-Niverse, he decides to publish Vince's literary efforts about a pink bubblegum character called Charlie. Meanwhile, Bob Fossil has embarked on a new breeding programme for the pandas.