A short-range orange ray fired from a zarogoth's mouth that leaves victims writhing rather than dead.
Zarogoth mobs fight with claws and a short-range magical ray. At the Larracos College of Magic gate, one of the Semeru Dwarves screams as an orange ray shoots from a zarogoth's mouth; he falls onto his back, and the mob laughs at him. Even after the monster is killed and the dwarf is drenched in its black oil, he keeps writhing in pain on the ground.
The Dungeon Anarchist's Cookbook is blunt about it: they're easy to kill once you figure out how they work, but their pain ray attack is no joke.
The zarogoths' signature attack, disabling defenders rather than killing them outright.