Primus singer, bassist Les Claypool wrote the original theme track and four other themes for upcoming Wii romp Mushroom Men, Billboard reports.

This is Claypool's first game to set music too, though he's created themes for both South Park and Robot Chicken as well as a number of movies.

The idea to approach Claypool about scoring came from Kris Taylor, co-founder and art director of Red Fly Studio, and a huge fan of Claypool and his band, Gamecock's Mike Wilson told me. Billboard misreported that the impetus came from Ryan Mattson. Wilson said that Taylor built his own Claypool-style bass, which thoroughly impressed the musician during his visit to Austin in March.

For Claypool, a fanatic mushroom hunter who has a gaming son, the decision was an easy one.

"After seeing the design material and mock-ups online," he says, "I knew at once this was an opportunity to gain massive brownie points with my offspring, so thanks, 'Mushroom Men!'"

Mushroom Men: The Spore Wars is due out Nov. 11 and will feature lyrics and instruments for the game's four major themes. The DS game, Mushroom Men: The Rise of the Fungi, due out Oct. 14, may also have some of the music.

As a bit of cross-promotion, Gamecock is sponsoring Jam Cruise 7, with Claypool headlining in January, and Jan Cruise 7 is running a sweepstakes with the grand prize winner getting a custom Mushroom Men art bass guitar signed by Claypool.

Les Claypool Scores 'Mushroom Men' Video Games [Billboard]