Terramorphous the Invincible

Terramorphous the Invincible is a boss in Borderlands 2. It is a thresher serpent with a powerful knockback attack that sends the player character flying into the air.

Terramorphous was conceived as a tougher follow-up to Crawmerax the Invincible found in the Secret Armory of General Knoxx DLC from the original Borderlands. Terramorphous appears in a quest named "You.Will. Die. (Seriously.)" According to Gearbox, the boss can be fought multiple times and will drop different loot each time, including Legendary items that can only be obtained by killing Terramorphous.