A one-of-a-kind Harley-Davidson Cross Bones motorcycle (above) customized by bad boy Brit artist Damien Hirst will be auctioned off for the L.A.-based Project Angel Food charity on April 23rd. Bidding for the one-off bike / sculpture, painted with Hirst's signature rainbow-hued spin design, begins at $100,000. Hirst applied his centrifugal force paint technique to individual parts of the retro-styled Cross Bones, the first model in Harley's new Dark Custom line, and then shipped them to the factory where the finished bike was assembled. The motorcycle is part of Angel Art, an event and benefit auction celebrating the 20th anniversary of the charity, which provides daily meals for people homebound or disabled by HIV/AIDS and other serious illnesses. The event, co-chaired by the likes of Tom Ford, Naomi Watts, Tobey Maguire and Robert Downey Jr., is taking place at L.A.'s Creative Artists Agency.