When Brendan Small (co-creator and writer of Home Movies) started his new show Metalocalypse in 2006, he had no idea the impact it would have.

The cult animated show follows the band Dethklok, a band so big they’re the world’s 7th largest economy. Small writes and records all of the show’s original songs, and has released 4 entire albums of material from the band.

However, after four seasons and one hour-long rock opera, the show’s production has stalled. Despite having a huge audience in re-runs (Small says “Over 1 million a week”), Adult Swim passed on financing season 5.

A fan campaign has been brewing since Small appeared at Comic Con in New York this past week, where he made an announcement on their live stream encouraging fans to tweet at Adult Swim and Hulu (who owns the licensing rights) to show their support.

Soon enough the fans began to storm social media, and it turns out some of the show’s biggest fans are fellow musicians. Anthrax, Mastodon, and Metallica themselves have all taken to Twitter and Instagram to plead for a satisfying finale to the show.

They were joined yesterday by veteran voice actor Mark Hamill (you might also know him as Luke Skywalker), who has been a cast member and fan since the show’s beginnings.