People say this a lot, but the entity that is Venom, isn't it really just a villain? Eddie is mostly an anti-hero because he has no ambitions at world domination of his own.....He just hates Parker and over the years, certain other heroes, and the Symbiote itself isn't really inherently evil, it simply wants to survive and be strong. My limited knowledge of it doesn't lead me to believe it acts out of spite or vengeance outright unless you disturb it's procreation.
So when combined, the two become a completely different thing....Venom....Who he, or them, themselves, seek destruction and power......Now in times when Eddie can control the parasite, he does kinda act as an anti-hero, and in time when the symbiote controls him, it's only seeking power and the death of those who oppose it...So at the end of the day, can Venom really be labeled as any of the things such as Hero, anti-hero, of villain?
Yes, I'm bored and high....Bout to get drunk.