Greek underworld his duty was to bring these souls to the underworld and no one would persuade him to do otherwise. Cerberus (Kerberos), or the "Hell-Hound", is Hades' massive multi-headed (usually three-headed) dog with some descriptions stating that it also has a snake-headed tail and snake heads on its back and as its mane. Born from Echidna and Typhon, Cerberus guards the gate that serves as the entrance of the underworld. Cerberus' duty is to prevent dead people from leaving the underworld. Heracles once borrowed Cerberus as the final part of the Labours of Heracles. Orpheus once soothed it to sleep with
Pluto (mythology) The tree was the white poplar (Greek "leukē"), the leaves of which are white on one side and dark on the other, representing the duality of upper and underworld. A wreath of white poplar leaves was fashioned by Heracles to mark his ascent from the underworld, an "aition" for why it was worn by initiates and by champion athletes participating in funeral games. Like other plants associated with Pluto, white poplar was regarded as a contraceptive in antiquity. The relation of this tree to the white cypress of the mysteries is debated. The "Bibliotheca" of Pseudo-Apollodorus uses the name "Plouton"