Os Mutantes ("The Mutants", Portuguese pronunciation: [uz mu?t??t?is]) are an influential Brazilian psychedelic rock band that were linked with the Tropicália movement of the late 1960s. It was formed by two brothers and a vocalist, but has gone through numerous personnel changes throughout its existence. After a hiatus from the late 1970s to the early 2000s, the band reunited for a tour in 2006.