Character from Hades by Supergiant Games
Sisyphus's boulder and best friend — large, mossy, spherical, and the subject of fierce debate regarding whether he is actually sentient.
Bouldy does not speak. Bouldy does not move on screen. What Bouldy does is receive Sisyphus's extended one-sided conversations with something that Sisyphus insists is understanding, and the evidence is difficult to dispute entirely. If you give Bouldy Nectar, something happens. Specifically, Bouldy apparently accepts it happily and gives a boon back. Whether this represents genuine sapience or an elaborate coincidence involving a very motivated boulder is a question the game declines to answer. He is the most loyal presence in Tartarus. Sisyphus chose to remain near him after his sentence was revised. That says something.
A large, spherical, moss-green anthropomorphic stone with a happy expression and stony facial features. Chained to Sisyphus with metal links. Not going anywhere.
Also known as: The Boulder, Bouldy