Sirens

Sirens are a race of long lived amphibious beings who have all existed since before recorded history. They typically inhabit the waters between Underside and Overside to catch trespassing demons.

Sirens do not reproduce so their numbers constantly wane and therefore at some point they will inevitably go extinct. In times long past, these creatures ruled the over world and subjugated humans as both slaves and food but at some point, some sirens who believed in living in peace with humans splintered off and rebelled.

The rebellion was successful and at the current time, sirens serve as protectors and guardians to humans. They achieve this by acting as white blood cells who catch and eat any Demons that try to escape the underside to reach the Overside, where humans dwell.

Sirens began their life as a small, slug-like clump of flesh with a protective side and a digestive side. Eventually, they adapted, becoming more complex. Different sirens chose different adaptations, some choosing to appear more human, others opting to forgo noses and standard mouth placements.

Siren's bodies are entirely hollow except for a stomach cavity which is present throughout the entire inside of their body. All entrances into the body lead to this stomach. When they take prey into them, they will eat them whole and digest them alive into a white viscous liquid which is them absorbed. This process does not seem to be painful as there are images depicting this happening with a smile on the victims face.

While sirens certainly do still enjoy the taste of human flesh, it is unlikely that one will attack a human, but not unheard of. This may partly be because of empathy but it's more likely due to other reasons as these ancient beings find it hard to empathise with non-Sirens. Sirens are very unlike humans in that they are all asexual, and do not usually feel emotions like love. The only case where this may be proven otherwise is in Felix's relationship to Cheese. which is never outright called love, but implies the possibility.

Sirens also have the ability to sing an enthralling tune which will lure in suspecting prey. Their song is capable of incapacitating most prey which allows the Siren to eat the now willing victim.