okay, Venom came to earth after the secret wars with spiderman, if you have ever seen spiderman in a 'black' suit, thats the sybiot (sp?) on him, after spidey works out its evil he rejects it, and it goes onto Eddie Brock (also mentioned in the first spiderman movie) and he becomes venom, when hes imprissoned, somehow part of the symbiot (i forget how) seperates from Venom and attaches to Cleatus Cassidy, the mass murderer, and becomes Carnage, who was alot worse than Venom, spiderman even teams up with Venom to beat Carnige (play the snes game Maximum Carnage, which i might add is fking impossible) and yeah, im no spiderman historian, but thats pretty much how it goes.