the Bone Wurm is the demonic version of the alien sand worms it spits out lost souls to murder a bro brutally and it also vomits fireballs like acid from the terrorkrawler. This boss is only in the later hell missions
TRIVIA: 1. After you kill a bone wurm it'll show the acid crawler parts due to a glitch.
2.when it vomits fireballs it is like the terrorkrawler.