Voracidous the Invincible, the new raid boss from Hammerlock's Hunt expansion.
Voracidous the Invincible is a new raid boss from Sir Hammerlock's Big Game Hunt DLC in Borderlands 2.
You can get the quest to fight him from Sir Hammerlock at the The Aegrus Sophisticates' Lodge after beating the DLC's main story (ending with "The Fall of Nakayama" quest)
After you get the quest, exit to Candlerakk's Crag then cross the bridge at Elite's Crossing and head to the waypoint, then pay 8 Eridium to activate a lever and enter the Rage Cage
There you will fight Voracidous who also summons Chief Ngwatu. Chief Ngwatu places some sort of shield on Voracidous which makes Voracidous immune to damage.
 Strategy Guide
Stay away from Voracidous when his shield is active
Try to have high resistance to shock damage
Kill the chief before he can transfer his shield to Vora. Varacidious still gets a boost but without the shield he is still easier to defeat.