What is the name of the serial killer who bonds with the Carnage symbiote?

The serial killer who bonds with the Carnage symbiote is Cletus Kasady. Together, Kasady and the symbiote become the supervillain known as Carnage.

Kasady was created by writer David Michelinie and artist Erik Larsen, first appearing in The Amazing Spider-Man #344 in 1991. He is portrayed as a deeply violent serial killer whose nihilistic worldview makes him an especially dangerous symbiote host. The Carnage symbiote is an offspring of Venom, and it bonds with Kasady after being left behind in a prison cell.

Because Kasady and the symbiote are both extraordinarily violent, their partnership is more destructive than the usual Venom bond. Carnage can reshape the symbiote into blades, tendrils, projectiles and other weapons, while also gaining superhuman strength, agility and regeneration. His red appearance and chaotic methods distinguish him from Venom’s darker but sometimes heroic characterization.

Readers sometimes confuse the host with Eddie Brock, but Brock is most closely associated with Venom. Cletus Kasady is the signature human identity behind Carnage, even though the symbiote has temporarily used other hosts in different stories.