Almost always performing in full nudity, setting guitars on fire and bringing weapons onstage was all in a day’s work for the Butthole Surfers, the legendary Texas band formed in the early 1980s after two accounting students, Gibby Haynes and Paul Leary, crossed paths. Their psychedelic rock, steeped in radicalism, chaos and unpredictability, left a lasting mark on a generation of musicians, from Nirvana to The Flaming Lips, as well as the early era of the Red Hot Chili Peppers.