Warning: SPOILERS for Avengers #66The Avengers have had many powerful members in their ranks, but no one beats the cosmic might of their latest recruit: Galactus. In a shocking twist, Galactus joins the Earth's Mightiest Heroes in their final battle against Mephisto and Doom Supreme for the fate of the Multiverse.

Avengers #66, by Jason Aaron, Javier Garròn, David Curiel, Morry Hollowel I, Erick Arciniega, and Rachelle Rosenberg, shows the final stages of the battle between the Avengers assembled from every world in the Multiverse by Avenger Prime (a version of Loki) and their foes, Doom Supreme with his army of Dooms and the Mephisto of Earth-616, who has killed and absorbed all other versions of himself, growing to colossal proportions and power. Luckily, Avenger Prime has already called in his most powerful reserves. Ka-Zar, who was thought lost during a dangerous time-traveling mission, returns armed with the Power Cosmic, and bringing his new master, Galactus himself, who is immediately declared an honorary Avenger.

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Ka-Zar Returns To Help the Avengers, & He Brings Galactus With Him

Galactus becomes an honorary Avenger

Ka-Zar was last seen in Avengers #50, when he was traveling through time on the Avengers' behalf to chart the history of Earth's legacy powers. He was caught by Mephisto's bodyguard, the Iron Inquisitor (Howard Stark), and left stranded on a Earth ready to be destroyed by Galactus. It turns out that Ka-Zar was able to make a deal with the Devourer of Worlds, becoming his new herald. He then promised Galactus "the meal of a lifetime" and brought him to the battlefield at the God Quarry, where Ka-Zar's new master will likely feast on the Doom Planet, a planet-sized version of Doom that is causing havoc among the ranks of the Avengers' army.

Galactus Is Officially An Honorary Avenger

Marvel Snap Galactus Art Used for Card of Cosmic Being About to Devour World

Rather than just being an unlikely ally, Galactus is officially declared an honorary Avenger, and he is even present in the final panel of the issue, a splash page with a huge "Avengers Assemble!" battlecry. This choice is consistent with the tone set by author Jason Aaron for his final Avengers tale. This long Multiversal saga has almost been trying to upstage itself, with every new chapter making the stakes and the cast of characters bigger and more impressive. The proof is that, just one page after Galactus' appearance, a new colossal cosmic Avenger is introduced with the arrival of Avengers Mountain, the corpse of a Celestial animated by the spirit of a Deathlok.

Declaring Galactus an honorary Avenger seems like a cheap way to create an impactful moment in the story, and some purist fans might surely turn up their noses at that. However, this is now part of the official Marvel canon, and from this moment onward every Avengers' history book will have to record Galactus as a member of Earth's Mightiest Heroes.

More: Behold 'The Army of Doom,' The True Enemy of The Avengers' Multiverse War

Avengers #66 is available now from Marvel Comics.