Venom: What Does The Ending Really Mean?
7. Cletus Kasady Knows Eddie Brock (And Might Have Already Bonded With Carnage)
Venom's first post-credits scene focuses on Eddie Brock personally being requested to interview renowned imprisoned serial killer, Cletus Kasady. The exchange isn't long, but it's implied that the murderer (really Woody Harrelson in a bad wig) knows about Eddie's symbiotic alter-ego, warning him that when he escapes his confines, there'll be "carnage".
Unless it's just a happy accident, the scene seems to suggest that Kasady's killings were helped in part by his own symbiote (reinforced by the FBI keeping access to the criminal to a minimum), setting up a conflict between the two aliens for the sequel.
The scene does admittedly raise more questions than it answers, however. For instance, how did Kasady encounter his own symbiote? Does the government already know about these lifeforms? Will Harrelson get a better wig in the sequel? The film only teases the answer to these questions, but it does offer a tantalising cliffhanger should there be a Venom 2.