Angry Birds Evolution is hosting a head-banging Halloween thanks to a partnership between game developer Rovio and metal band Iron Maiden. The two-week celebration transforms Bird Island into a battleground that pays homage to Iron Maiden, its mascot Eddie the Head and the heavy metal universe as a whole.

“Angry Birds Evolution is a game built for an older audience with tons of interesting pop culture references, really crazy looking birds and sometimes even with somewhat dark humor,” Miika Tams, vice president of games and product lead for Angry Birds Evolution told AListDaily. “The game’s version of Bird Island can contain pretty much anything—we always aim to surprise the audience with something that they would not be expecting to see. Obviously, [including] Eddie the Head and Iron Maiden is a great example of telling an unexpected story.”

Through November 1, Eddie the Bird—an avian version of Eddie the Head—is a collectible character in the game, and his four evolutions represent four different album covers from Iron Maiden. Players who successfully recruit Eddie the Bird to their team during the Halloween event will get to keep him forever.

The team at Rovio are fans of the band, and Iron Maiden’s many album covers provided no shortage of inspiration from demons to Egyptian pharaohs. Tams told AListDaily that they wanted to pay attention to every detail when translating Iron Maiden’s aesthetic to the game.

“It is actually quite surprising how well Eddie fits the Halloween version of the game,” said Tams. “Evolution´s Halloween and Eddie [may sound] very surprising and somewhat strange, but when you see the game, it is actually very natural fit.”

Angry Birds Evolution may be one of many spin-offs in the popular franchise, but teaming up with Iron Maiden represents new territory for the Finnish developer.

“This is the first time Rovio has partnered with Iron Maiden and Eddie the Head,” explained Tams. “This is also the first time Iron Maiden has partnered with a mobile gaming brand, the first time Iron Maiden has allowed a partner to use their typography and the first time Rovio has changed the typography of Angry Birds to a partner’s font. A lot of firsts.”

Rovio is finding “birds of a feather” with musicians across the world and has partnered with artists like Shakira and De La Soul in the past.

Iron Maiden has its own official mobile RPG game called Iron Maiden: Legacy of the Beast that will incorporate Eddie the Bird sometime next year. The free game puts players in the role of Eddie in one of his many forms to create teams and battle through multiple worlds with turn-based combat. The band declined to comment for this article.

Rovio will be offering exclusive Eddie the Bird merchandise to fans throughout the event, although Rovio was unable to share details at this time.

“The team is a big fan of Iron Maiden, and we are super excited about how well Eddie the Head fits in Angry Birds Evolution,” said Tams. “Even Iron Maiden’s music fits very well with the game. This truly is the most metal Halloween campaign ever.”