The trapper t and the lurker above t are the only members of the t trapper or lurker above monster class. They hide and wait for unsuspecting victims before swallowing them whole and digesting them alive.
Trappers and lurkers above are almost identical. The only differences are that trappers have a higher base level and a slightly more damaging attack, but cannot fly.
Both monsters are easy to detect via telepathy or warning, and they are also very slow, making them less fearsome than their attack would suspect. However, they can digest any pet in one turn just like a purple worm can, so be careful not to lose a good pet to them.
Both monsters are silent, can hide, have an animal body, have no eyes, limbs or head, are carnivorous, always start hostile, can stalk, are strong, and can be genocided.
Their bodies are flat. They wait hidden on the floor and close up on their victims.
The trapper is a creature which has evolved a chameleon-like
ability to blend into the dungeon surroundings. It captures
its prey by remaining very still and blending into the
surrounding dungeon features, until an unsuspecting creature
passes by. It wraps itself around its prey and digests it.
They resemble rays (the fish). They hide and drop from the ceiling, engulfing their victims.
In contrast to Dungeons & Dragons lurkers above, Nethack's lurkers above have no eyes.
These dungeon scavengers are very adept at blending into the
surrounding walls and ceilings of the dungeon due to the
stone-like coloring of their skin.