When young Jessica Drew suffered uranium poisoning in 1931, her father was forced to inject her with his untested spider serum and seal her in a genetic accelerator.

Jessica possesses superhuman strength (can lift at least up to 7 tons), endurance and speed. She can focus her bio-electric energy into "venom blasts" sufficient to stun or kill normal humans, and she can also adhere to almost any surface. Jessica rapidly forms an immunity to all poisons and drugs, and is totally immune to radiation. Her metabolism generates pheromones which attract human males while repulsing females, though she uses a chemical "perfume" that can nullify this effect. Jessica has lost and regained her powers more than once, but has recently emerged with her powers restored greater than ever.