While Ben Reilly was acting as Spider-Man in place of Peter Parker, there was an incident where the Carnage symbiote left its host Cletus Kasady and escaped the Ravencroft insane asylum. To keep it from hurting anyone, Ben took the symbiote and allowed it to bond to him, becoming Spider-Carnage. Ben was able to keep control of himself and the symbiote until he could get help to remove it and force it back onto Kasady in Ravencroft.
Positively Jim 