Lurker

Lurkers were aberrations found in the Underdark.

Description
Lurkers physically resembled manta rays but were much larger. Their underside was grey and had a texture similar to that of stone.

Abilities
Lurkers were nearly impossible to detect, thanks to their excellent camouflage.

Combat
Lurkers hunted by hiding along the top of caverns and tunnels, attaching themselves with their camouflaged underside facing downwards. Once a target passes underneath, it dropped from the ceiling, slamming into them and wrapping itself around its prey. It killed its prey by constriction.

Ecology
As omnivores, lurkers ate whatever they could. Female lurkers laid a clutch of eggs in a sticky substance on the ceiling of a cave or tunnel. After hatching, the newborn lurkers fell to the ground, where they fed on small creatures until they grew strong enough to fly on their own. Since they were solitary creatures, the young were left to fend for themselves.

Lurkers flew due to a gas they naturally generated in internal sacs.

Uses
Lurkers were sought after to be trained and employed as defensive creatures. As such, lurker eggs could be sold for up to 900 gp and a newborn lurker up to 1,100 gp. The gas generated by lurkers could be used as a material component in the brewing of a potion of levitation.