1. Death by Carnage:
One of Venom's most notable deaths came in the 1993 "Maximum Carnage" storyline. Venom was killed by Carnage, a villain created when a serial killer bonded with the Venom symbiote. Carnage ripped Venom apart and absorbed his symbiote, becoming even more powerful.
2. Death by Anti-Venom:
In the 2008-2009 "Dark Reign" storyline, Venom was killed by Anti-Venom, an antibody-based symbiote created by the government to destroy the Venom symbiote. Anti-Venom bonded with Eddie Brock and purged him of the Venom symbiote, leaving him as a normal human.
3. Death by Knull:
In the 2020-2021 "King in Black" storyline, Venom was killed by Knull, the god of the symbiotes. Knull was able to take control of the symbiotes and use them to invade Earth. Venom fought against Knull, but was ultimately overpowered and defeated.
However, in each case, Venom has been able to find a way to come back. He has either been resurrected by the symbiote, or he has found a new symbiote to bond with. This has allowed him to continue his career as a superhero and protector of the innocent.