As we've reported -- a lot -- Metallica have been celebrating their 30th anniversary for the past week with a series of shows at the Fillmore in San Francisco.
The shows have featured a rotating cast of special guests that makes it seem like virtually everyone wanted to wish Metallica a happy 30th birthday.
Among those who sent along their birthday wishes were Green Day, who posted a video of the band covering the Misfits classic "Hybrid Moments" in honor of Metallica. You can check out the video below. Billie Joe doesn't do a half bad Danzig, does he?
Green Day are reportedly working on the follow-up to 2009's 21st Century Breakdown.