Rabid is a 1977 Canadian drama horror film written and directed by David Cronenberg. It features Marilyn Chambers in the lead role, supported by Howard Ryshpan, Joe Silver and Robert A. Silverman.
Chambers plays a woman who, after being injured in a motorcycle accident and undergoing a surgical operation, develops an orifice under one of her armpits. The orifice hides a phallic stinger that she uses to feed on people's blood. Those she feeds upon become infected, whose bite spreads the disease.
(Summary from Wikipedia)