thats a cuttlefish.
this type of lovecraftian nightmare fuel horror is actually just a cuttlefish that ended up buried in the sand with no explaination.
this creature has camoflauge so this flat cuttlefish can go invisible like its cousin the octopus.
and also they are venomous but not that dangerous to humans.
and by the way their diet consist of crustaceans, small fish and marine invertebrates so humans are not on its menu.
and by the looks of it. its dead
so in the moral of the story: the humans just found a dead cuddlefish buried it in the sand and picked it up like if they were indiana Jones.
