Who was Hades guard?

Hades, the Greek god of the underworld, was primarily guarded by Cerberus, a three-headed dog that prevented the dead from leaving and the living from entering the realm of the dead. Cerberus was often depicted as a fearsome creature, embodying the ominous nature of the underworld. In addition to Cerberus, Hades had other lesser spirits and beings, such as Charon, the ferryman who transported souls across the River Styx.