WARNING: The following article contains spoilers for Man-Bat #4 by Dave Wielgosz, Sumit Kumar, Romulo Fajardo Jr. and Tom Napolitano, on sale now.
In the DC Universe, the Venom serum is synonymous with Bane. The enhanced steroid gave the Santa Priscan strongman the strength to break Batman's back. Along with his cunning intellect, it's a key part of what makes him such a major threat to the Dark Knight.
While Bane has put Venom to use most consistently, he's not the only character to do so. Many characters have used the drug to enhance themselves. Not all of them are Batman villains, or even supervillains at all.
Man-Bat
The three-way battle between Scarecrow, Batman, and Man-Bat came to a head in Man-Bat #4. Batman suffered the effects of Scarecrow's new weapon, a sonic cannon. It brought out his worst impulses and made him see Man-Bat as his greatest foe. A confrontation with this twisted version of Batman forced Man-Bat to take his "last chance cure" for the cellular degeneration that's killing him, Venom. While Man-Bat's alter ego Kirk Langstrom hoped the Venom would strengthen his degenerating cells, Man-Bat hopes it will lead him to the same dominant victory over Batman Bane enjoyed.
The Riddler
Before his battle with Batman in 1993's Batman #490, by Doug Moench and Jim Aparo, Bane used a Venom-enhanced Riddler to soften him up. After solving one of his riddles before Batman could, Bane shot the Riddler with Venom-tipped darts. The darts empowered Riddler with super strength and durability for 48 hours. Still, the villain proved unable to convert his first physical advantage over Batman into a victory. Batman's tenacity frustrated him, forcing him to run away.
The Riddler had Batman on the ropes in their rematch. Unfortunately, his physical enhancements didn't make him immune to being shot by Bane's henchmen, who saved Batman's ultimate defeat for their boss.
The Scarecrow and Colin Wilkes
In 2008's Detective Comics #848, by Paul Dini and Dustin Nguyen, the Scarecrow used Venom to turn 10-year old orphan Colin Wilkes into a monster in an attempt to put Batman in an unwinnable situation. Batman saw through his plan and turned it against him by tying Colin's beloved teddy bear to Scarecrow, enraging the mutated boy. Batman saved the Scarecrow's life by severing Colin's Venom lines.
Colin retained the ability to transform into his Venomized self and became the vigilante Abuse. He would team up with Damian Wayne to take down a children's fighting ring run by Mr. Zsasz's. Damian even gifted him a tricycle, which he called the Cycle of Abuse.
Lex Luthor
Looking for an advantage in an impending battle with Superman in 2004's Superman/Batman #5, by Jeph Loeb and Ed McGuinness, President Luthor injected himself with his own variant of Venom, which combined the super steroid with synthetic Kryptonite. Donning his battle suit from Apokolips, Luthor thought he was a match for the Man of Steel.
One of the side effects of the drug is madness, which caused Luthor to indulge in the villainous cliche of monologuing at the worst time. He admitted to Superman and Batman that he'd traded Doomsday to Darkseid in exchange for weapons during Our Worlds At War. Batman recorded his ranting, giving him the evidence he needed to end Luthor's presidency.
Batman
In Dennis O'Neil, Trevor Von Eeden and Russell Braun's Batman: Legends of the Dark Knight #16, Batman was the first DC character to use, and abuse, Venom. He started taking Venom after failing to save the life of Sissy Porter, a child being held for ransom. Her father, Doctor Randolph Porter, created Venom as a designer drug. Batman started taking the drug to push past the physical limitations that caused him to fail.
The drug successfully enhanced the Dark Knight, but Batman realized he'd become addicted to it. He quit cold turkey, detoxing in the Batcave for a month. Proving the strength of his willpower, Batman kicked his addiction and was able to stop Dr. Porter and Army General Timothy Slaycroft from creating more Venom enhanced super soldiers.
The Joker
The most audacious use of Venom wasn't in a DC Comic. The final boss fight of 2008's Batman: Arkham Asylum video game is a monstrous version of the Joker empowered by Titan, a Venom variant created in part with Bane's blood. Beyond making a monster out of its users, Titan also caused insanity, which wasn't much of a stretch for the Joker.
However, the drug also adversely affected his intelligence, which allowed Batman to come up with a strategy to defeat him despite Joker's greatly enhanced strength. Joker's exposure to Titan had serious consequences as well, leading to his death in the game's sequel, Arkham City.