Never got to fight Vermivorous on 360, been trying on HC in TVH & UVH mode but still have no luck. Even with 3 guest profiles logged in, no verms spawn. Plenty of ultimates & 2 even dropped Quasars but still no Vermivorous. Am lvl 72 gunzerker, can farm either mode with 3 other lvl 72s minimum. GT: Destroyah340
Try it on WamBam Island at the beginning of the Main quest there. You have to inject a varkid or something and at the time this quest is active they spawn endlessly.