For those of you who have never heard of it - and I counted myself as one of those - The Toxic Avenger is a 1984 comedy monster horror mashup B-movie that earned cult status as a kooky flick with lots of ridiculous gore. Horror movie geeks and theatre nerds aren't the most obvious bedfellows, but this musical adaptation - getting its European premiere at Southwark Playhouse - will definitely satisfy both hoards.

This is a show with its tongue firmly in its green, goo-filled cheek. From the moment it begins, with the song "Who Will Save New Jersey" - where we're told the state has become Manhattan's dumping ground for toxic waste - to the moment they rhyme cranium with geranium, this musical is all about the laughs. And in Benji Sperring's excellent production they really deliver.

The story is the classic Spiderman-esque double identity yarn with plenty of weird twists. Melvin Ferd the Third is in love with a blind librarian Sarah who isn't returning the affection. When he decides to impress Sarah by messing with the mayor's lucrative toxic waste disposal plans, he is dumped into a vat of very nasty looking stuff by her thugs. He emerges as Toxie - think a mixture of Hulk, Shrek and Sloth from The Goonies. He then vows to try to help the residents of Tromaville in the fight against the environmental catastrophe enveloping their city.

Joe DiPietro's book and lyrics are full of all-American high-school-style gags with a hilarious handful of double takes and double entendres. The blind librarian is responsible for a lot of the jokes - there are even several exits where she loses her white cane and has to crawl slowly offstage. And though the plot is as familiar as your front door, it's delivered fast, furiously and with a wonderfully rough around the edges quality.

But what really catapults this production to superhero status is its five-strong cast. Where Hannah Grover and Mark Anderson play the two leads, Ashley Samuels, Marc Pickering and Lizzii Hills are an ensemble that make the backstage quick change into a work of art.

Samuels and Pickering play a multitude of characters - everything from police chiefs to mad scientists to hairdressers - with a wonderful bout of OTT camp about them. Hills is also magnificent as both Melvin's mum and the masochistic sex-driven mayor. There's one scene where she plays both of them in the same song and it's just complete madness.

Grover gives a stand out performance as the erotically-charged Sarah whose obsession with Oprah Winfrey leads her to sing the hilarious "Choose Me Oprah!" and her cavorting about the stage in "Hot Toxic Love" is genuinely a work of comic gold. She is a cute as buttons blind sexual predator and there is no stopping her.

In the designs, Mike Lee's nuclear waste barrels adorn the stage and bubble nasty-looking green gloop while Nic Farman's lighting bathes everything in a sickly bright purple and green sheen. There's a lovely scrappy sense about the whole thing.

It may not be a square jawed, toned-torso hunk, but musical theatre needed a hero and The Toxic Avenger is most definitely it.

The Toxic Avenger runs at Southwark Playhouse until 21 May.