The Rage Cage is the home to the new raid boss, Voracidous the Invincible, in the Hammerlock's Hunt DLC in Borderlands 2

The Rage Cage is a location in Sir Hammerlock's Big Game Hunt DLC in Borderlands 2.

It is located past Elite's Crossing in Candlerakk's Crag

You need to pay 8 Eridium to use a lever that will take you to the Rage Cage

In this are you find the raid boss, Voracidous the Invincible