The Hundred-Handers, Cottus, Briareus and Gyges, were three monstrous giants, of enormous size and strength, with fifty heads and one hundred arms. They were among the eighteen offspring of Uranus (Sky) and Gaia (Earth), which also included the twelve Titans, and the three one-eyed Cyclopes. According to the Theogony of Hesiod, they were the last of these children of Uranus to be born, while according to the mythographer Apollodorus they were the first. In the Hesiodic tradition, they played a key role in the Greek succession myth, which told how the Titan Cronus overthrew his father Uranus, and how in turn Zeus overthrew Cronus and his fellow Titans, and how Zeus was eventually established as the final and permanent ruler of the cosmos.

According to the standard version of the succession myth, given in the accounts of Hesiod and Apollodorus, the Hundred-Handers, along with their brothers the Cyclopes, were imprisoned by their father Uranus. Gaia induced Cronus to castrate Uranus, and Cronus took over the supremacy of the cosmos. With his sister the Titaness Rhea, Cronus fathered several offspring, but he swallowed each of them at birth. However, Cronus' last child Zeus was saved by Rhea, and Zeus freed his brothers and sisters, and together they (the Olympians) began a great war, the Titanomachy, against the Titans, for control of the cosmos. Gaia had foretold that, with the help of the Hundred-Handers, the Olympians would be victorious, so Zeus released them from their captivity and the Hundred-Handers fought alongside the Olympians against the Titans and were instrumental in the Titans' defeat. The Titans were then imprisoned in Tartarus with the Hundred-Handers as their guards.

The lost epic poem the Titanomachy (see below), although probably written after Hesiod's Theogony, perhaps preserved an older tradition in which the Hundred-Handers fought on the side of the Titans, rather than the Olympians. According to a euhemeristic rationalized account, given by Palaephatus, Cottus and Brriareos, rather than being hundred-handed giants, were instead men, who were called the Hundred-Handers because they lived in a city called Hecatoncheiria ("Hundredarm"). They came to the aid of the residents of the city of Olympia (i.e. the Olympians) in driving away the Titans from their city.

That slight smile and opalescent eyetone washed over Radhiya’s face once more. “I’ll see you at the treehouse tomorrow, then.”

“Wait-! What treehouse-”

But his body solidified and the world spread into the dark blanket beneath his legs. His eyes flicked from left to right while he prayed it wasn’t just some sort of dream. One leg, then the other, moving just fine. Yet he didn’t remember sitting on the bed, and the window was closed…