The Venom symbiote (of Earth-807128) is an alternate version of the symbiote. Unlike most other variations, this one does not have a host.
Not much is known about this symbiote except in the "Old Man Logan" reality, it followed Logan and Hawkeye through the Black Hills of South Dakota. It eventually bonded with a Savage Land T-Rex and attacked them, only to be stopped by one word from Black Bolt, "Stop.", followed by unbonding with the T-Rex.