This series is where I pick two fictional characters from anything list off their feats and abilities then, decide on who I think would win based off the facts. Note that this is my unbiased opinion.
Combatant one: Venom A symbiote species. Grants all users super strength and the ability to cling to most surfaces. Limited shape shifting. (forming spikes or expanding size. Invisibility through camouflage. Ability of the symbiote is to fight or defend it and the host in danger. Dimensional aperture. (allows host to conceal things without adding mass) Telepathic connection with host. Web capabilities such as Spiderman and the symbiote is immune to spider sense. Exhibits immunities to supernatural powers. Able to lift 13 tons with all his force. Able to replicate. Vulnerable to fire and sonic waves.
Combatant two: Swamp Thing Superhuman strength and durability. Telepathic dominion over plant life. Vegetation body granted shape shifting and hyper elasticity. Able to create new bodies out of plants. Body damage is little to him as he can regrow damaged or severed body parts. Can transport across the globe to whatever vegetable matter is present. Immortality. Self-sustenance. (ability to nourish oneself) Flight.
WINNER: Swamp Thing There isn't a lot to go off of that states that Venom can beat this guy. His power is too diverse not to mention he use to wield fire. Venom can multiply but, not saying much Swamp Thing can control all plants on earth, that's easily an outnumber. Venom is strong but, bodily damage is useless and so are his claws. His webs are also useless considering that Swamp Thing can switch to any other plant life. Swamp Thing is immortal and isn't going to be knocked out for Venom to win, to be honest Swamp Thing is in a whole other league!