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.

Bollo, the eldest and most respected gorilla at the Zoo-niverse is gravely ill. Bob Fossil persuades Howard to dress in an ape suit, replacing Bollo, so that he can continue accepting sponsorship money for the gorilla. Everything's going smoothly until the Grim Reaper arrives and mistakenly takes Howard to Ape Hell instead. Vince sets off to rescue Howard and they run into trouble when they encounter the Ape of Death who is plagued with problem hair.

In an attempt to compete with daring adventurer Dixon Bainbridge, Howard and Vince set off in search of the Egg of Mantumbi - with the assistance of Gary Numan. Into the whiteness, the nothingness of the Arctic Tundra, the boys come face to face with hideous ice demon Black Frost. Luckily, Vince has befriended a polar bear.

Dixon Bainbridge, owner of the Zoo-niverse, is intent on selling to the highest bidder. There's a road being built through it and ‘if the animals won't work on it, they'll be underneath it'. Howard and Vince embark on an arduous trip deep into the Jungle Room, in search of the only man they think can help save the zoo - Howard's hero, Tommy Nookah.

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.

Vince is convinced that The Human League invented music. According to Vince, Howard's past career as a jazz trumpeter does not measure up. When Vince is offered a chance to join a new band, ‘Kraftwork Orange' with Johnny Two Hats and the Electro Girls, he's intent on leaving everything behind, including Howard.

After Ivan the bear becomes angry and escapes from his cage, Fossil arranges a place for Ivan at an Animal Offenders Institute. All Howard and Vince have to do is get there and back, in one piece, without falling foul of the Hitcher.

Vince and Howard are struggling to find the new sound needed to secure them a record deal with Pie Face Records. They enlist the help of Naboo who tells them the tale of musical gurus Rudy Van Disarzio and Spider Dijon, who only found their new sound after saving a town full of women from the evil Betamax bandit.

Howard takes acting lessons to overcome stage fright and get work with director Jurgen Haabemaaster.

Reluctant to celebrate his birthday, Howard finally succumbs to Vince's plan for a huge party.

When another bad gig is put down to Howard being old and past it, the boys use Naboo's magical amulet to transport themselves to the Fountain of Youth, where they hope to turn back the clock. However, to get there they must first go through the Desert of Nightmares where they encounter an evil cockney Sultan, a rebel army and Sandstorm, a beast made of sand that is incapable of love.

When Vince bites a rare jazz record, the Jazz Beast enters his bloodstream.

During a break at Kodiak Jack's reclusive log cabin, Kodiak tells Howard of the mythical Yeti that lives in the forest. His desire for fame and fortune gets the better of him and Howard trades Vince for directions to the Yeti's lair. However, things don't go according to plan when the Yetis kidnap Howard and Vince is propositioned by a maniac trapper.

Naboo and Bollo are off on the Head Shaman's stag do, leaving Howard and Vince in charge of Nabootique.

When imitators Flighty Zeus steal their thunder, the boys unleash the 'Crimp'.

The Crack Fox enters Nabootique and steals a precious bottle of Shaman Juice.

In an attempt to impress two goth girls, the boys stage a seance in their front room. Trouble ensues when they summon the most evil demon known to man, an old lady called Nanatoo, who does a runner with their flatmate, the Shaman Naboo's, most magic book. Naboo is livid and gets drunk, leaving it up to Howard and Vince to find the demon, retrieve the book and prevent Nanageddon.

While marooned on a desert island, Howard sees an opportunity to nurture his poetry and Vince takes to making bamboo fashion lines. However, with no-one to talk to but each other and nothing to eat but rancid coconuts, they soon find themselves in the midst of a coco-nightmare.

Following a somewhat poorly received gig, the boys decide to skip town for a bit. They take in a spot of fishing on Black Lake where, angry at Vince's fishing success, Howard sends him back to the local pub. Whilst Vince swaps tales with the locals at the King Prawn's Head, Howard is abducted by Old Gregg, the eerie merman who haunts the lake's waters.