the head of the creature , complete with three shark-fin shaped protuberances stemming out from its hairless and bulbous cranium , appeared to be gently lolling from side to side within its luminescent and briny prison , and even though encased behind glass , the creature still exuded an undefinable but , none the less menacing , aura of malevolence that unblinkingly shone out from behind those ostensibly visionless and deep set eyes .