Source: Souls for Smuggler's Shiv, pg(s). 86-87
A tuyewera is a monstrous undead creation used as an assassin by powerful necromancers.
Invisible in the daylight, a tuyewera's true form is revealed at night: a rotting humanoid figure whose legs have been severed at the knee, with decayed organs and bones protruding through tears in its flesh. Its jaw is distended and unhinged, and an impossible long tongue protrudes from it, moving of its own volition like some sort of hideous tentacle.
In addition to their daylight visibility, a tuyewera has the ability to steal the tongue from a recently slain victim. This allows the tuyewera to speak and understand all the languages known by the dead body, and the voice sounds exactly like that of the dead creature while it was still alive. A tuyewera can use the voice of one of their victims to lure creatures into a trancelike state and compel them to approach. Once within range, the tuyewera may constrict their victim with their tongue, or steal the breath of a controlled creature.