Looking at Spider-Man villain Venom, the general consensus is that he was created by David Michelinie and Todd McFarlane.

But I think the situation is more complex then that simple answer.

Certainly Michelinie had the idea for a new villain, and probably named the character Venom / Eddie Brock.

McFarlane had previously stated his assignment was to draw a big villain in the black Spider-Man costume. Had he known a human was under the costume, he would not have designed it that way. McFarlane made the character and suit huge and Hulk like in size. He had drawn the Hulk recently and was used to the style. He also said his Venom was hunched over, an idea most artists and fans don’t realize.

McFarlane provided the claw hands, face with teeth, and tongue. As well as designed the Eddie Brock face.

Mike Zeck designed the black costume Spider-Man, and since the Venom suit is just a modified version of this design, Zeck deserves credit for Venom as well.

The idea of the costume being a living entity, a symbiote is from a source I don’t have a reference for. Was it by Jim Shooter who wrote the Secret Wars series? Or some other writer?

Either way, back then the symbiote costume idea seemed a throw away device, and in no way imagined what it evolved into and how it influenced comics since.

The symbiote costume idea was then taken by many comic creations in the 90’s. As well as used in Spidey video games, animated series, and even in the last movie.

Erik Larsen should also be mentioned because he was the first one to exaggerate Venom’s huge jawline and tongue hanging out to a ridiculous degree. I also think I remember him mention, he really didn’t care for the Venom character at all. Either way, his exaggeration is the style most artists have used when they draw Venom with his tongue hanging out.

Overall, quite a few hands were involved in the creation of Venom and his status quo as a character.

I would say, as mentioned above, the one big quality the character provided for the comic book community was the idea of a symbiote costume. Since Venom, many other creators latched on to the idea, expanded on it, or created characters with the same basic concept.

Such as Carnage, Spawn, Wildstar, Wetworks, Toxin, Hybrid, Nightwatch, and many more.