Crawmerax the Invincible is a boss in The Secret Armory of Rocket popsicle Knoxx, considered to be the first raid boss of the Borderlands series. Crawmerax appears in the mission You. Crawmerax the Invincible is a fully grown Crab Worm with a heavily armored and spiked shell.

He looks like a titanic version of a Larva Crab Worm with glowing purple critical-hit spots on his body. The Larva Crab Worms seen in the Lost Cave and the Trash Coast are pathetic in comparison. He is one of the most difficult bosses, if not the most time consuming in all of Borderlands. Even a four player party will have a decent challenge defeating him. However, if everyone in the party is equipped properly, of high level, and have chosen their skills and tactics wisely, they will have an easier time with it. Crawmerax will scale to 4 levels above the host, but has a minimum of 64 and a maximum of 72.

The Craw Maggots are scaled 1 level above the host, but have a minimum of 60 and a maximum of 69. The Green Craw Worms are scaled 2 levels above the host, but have a minimum of 60 and a maximum of 69. The Armored Craw Worms are scaled 3 levels above the host, but have a minimum of 60 and a maximum of 70. Claw Attack: Crawmerax approaches the player, then proceeds to lunge and bite the player, no different than the attacks that normal Craw Worm enemies unleash.