The Beast is a unique player and NPC featured in Grand Theft Auto V and Grand Theft Auto Online.
Hunt the Beast
When the Freemode Event begins, players opt into a vote to become the Beast, and after 5 minutes, the game picks a random player out of those who opted in to be the Beast. From here, the Beast goes incognito in the in-game map and has to reach 10 landmarks without being hunted. The player has unique abilities, such as super jump, fast running and super strength, while having to reach each landmark.
Beast vs. Slasher
Later, as part of the Festive Surprise 2015 update, the Beast returns as a protagonist in the Adversary Mode, "Beast vs. Slasher." In this Adversary Mode, the Beast is up to fight against the Slasher, which was featured in an Adversary Mode beforehand with the same name. This Adversary Mode plunges the city into darkness while the Slasher and the Beast are up against each other. Slasher is equipped with weapon loadouts, while Beast uses his own unique abilities.
With the release of the aforementioned updates, the player is able to fight the Beast in Grand Theft Auto V. This can be done by collecting all 7 golden Peyote Plants. Once complete, the player is able to play as a Sasquatch in Director Mode. When playing as the Sasquatch, entering the south-eastern corner of the Thomson Scrapyard will result in the weather pattern changing, and the Beast will spawn on the roof of a plane fuselage. The Beast will act hostile towards the Sasquatch, retaining his fast running and super jumping abilities, however he is much weaker than how he is in said Online missions (due to the strength properties applying to the GTA Online protagonist's health system rather than the character model itself,) and can be taken down easily by the Sasquatch. The Sasquatch is also very quick and very strong in Director Mode.