Gorgon

Gorgon or Catoblepas is a very dangerous monster making its lairs in mountain caves. It is either very hostile or powerful enough that both werewolves and witchers show extreme caution to not wake one and to move as quickly and quietly away from their lair – all the while looking over their shoulders to make sure it hadn't awaken.

Its rare meat was favourite dish of princess Adda the White.

Manuscript Discovered in a Dragon's Cave
According to Sapkowski's Manuscript Discovered in a Dragon's Cave, “Catoblepas” means “looking downwards”, as the head of this exotic creature similar to an armored buffalo is so heavy, so the beast constantly stares down, to earth. And that's fortunate, for the Catoblepas is so full of poisons so it kills all the life at place by its breath or gaze. And it comes from that Catoblepas feeds on poisonous herbs, grasses and prickly bushes which no other animal dares to touch. Therefore another name of that beast is Gorgon, because much like the Greek Gorgon it kills by its gaze.