This is Gwar (2021)

The powerful story of the most iconic heavy metal/art collective/monster band in the universe, as told by the humans who have fought to keep it alive for over thirty years. The feature documentary includes interviews with the band members, both past and present, as well as other artists including Weird Al Yankovic, Thomas Lennnon, Alex Winter, Bam Margera, and Ethan Embry, including never before seen footage of legendary GWAR frontman Dave Brockie.