Slipknot

Slipknot is an assassin who can climb anything. He was captured and sent to prison. He joined the Suicide Squad during the Midway City Crisis, and tried to escape. This resulted in his being blown off by the bomb in his neck, killing him.

Trivia

 * Slipknot will join the Suicide Squad in Nighlock and the Suicide Squad. His head was blown off by the bomb injected into his neck by Rick Flag when he tried to escape.