I dunno if there is a named version just called "Death Beetle" (There should be, there was in original Nagafen's Lair). But the only one I've seen in Naggy's Lair revamp so far is actually called "a death beetle". Is level 100, not 103, and appears to just be a trash mob. It's probably the PH for this named though so I'd keep both mobs in this zone until confirmation otherwise...
-Rainbow Dash