I am 100% certain this is a giant antlion, Google it. Star Wars took inspiration from the animal when making that giant sand monster thing. They're really amazing creatures in real life and turn into a voracious beetle when fully mature.
Edit: I'm super excited here because for once I know what the damn thing is! (Also in true ark form they have altered the creature into a worm, putting their own spin on it, but behaviorally, this is the creature depicted in the dossier)
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