Zombies

The Zombies are flesh-eating undead found on a few of the many Earths within the Multiverse. Their wider story is largely unknown, though at some point an unidentified virus swept across one Earth, reanimating the dead and driving that world into an apparent global apocalypse.

Angstrom Levy once stumbled upon a dimension overrun by the plague and hurled Invincible into it during their fight. Invincible managed to slip past the swarm and reach a band of survivors, warning them about Angstrom Levy and his predicament before a portal back to his own world opened.

As reanimated corpses the Zombies are far less intelligent than living people, able only to groan the word "meat" when a healthy human is near, and they fixate on devouring flesh of any kind. Their dead bodies absorb enormous punishment, enduring mutilation, decay, and starvation, so that destroying the head appears to be the only certain way to put one down. They are strong enough to tear the limbs from their victims, and their bite passes the reanimating virus along through saliva, as the bite marks on many of them suggest.