Red Hood Gang

History
Red Hood Gang was a criminal gang in Gotham.

The gang was hired by Edward Nygma (acting on Phillip Kane's orders) to bust a party and kill Bruce Wayne. During a robbery in Ace Chemicals its leader fell into a vat of chemicals after fighting Batman. Soon after that gang was quickly caught.

The new Red Hood Gang was the Order of Saint Dumas - a motorcycle gang. They named themself that, as Dumas' helmet began to rust.

Trivia

 * It's possible Joker was the Red Hood Gang's leader who fell into the vat of chemicals.
 * The gang bust was Barbara Gordon's first team-up with Batman and Robin.