A monster which was appointed in Tartarus to guard the Cyclops. It was killed by Zeus when he wanted the assistance of the Cyclops against the Titans. (Apollod. i. 2. § 1.) Diodorus (iii. 72) mentions a monster of the same name, which was slain by Dionysus, and which Nonnus (Dionys. xviii. 237, &c.) identifies with the former.