This boss lacks any eyes, has big visible teeth and its jaws are always open with a black tentacle coming out of it.
Plot Importance (spoilers!)
It is heavily implied through dialogue (and somewhat confirmed during the cutscene where Alex
kills Judge Holloway
) that the Sepulcher is meant to be a representation of, or at least a physical embodiment of Joey, the Mayor's missing son. It is implied that Joey was buried alive by his own father, Mayor Bartlett
, as a sacrifice to their God. This is also implied on the monsters name, which is naturally another word for "tomb".