You'll need a fully completed story save to start hunting the beast, though not every side mission needs to be done. The golden peyote plants spawn in different spots around raton canyon, alamo sea, and throughout san andreas but timing is absolutely critical here your best window is during foggy conditions on pc or snowy weather on consoles. The plants only appear one per day of the week, with specific coordinates for each spawn like friday's spot north of the drainage ditch under those trees, and saturday's location on the ridge above grapeseed farms.

Make your way to the raton canyon lookout platform first, since that's a reliable starting point for tracking these things down. When you find a plant, eating it triggers the transformation sequence and temporarily lets you rampage around as the beast pretty wild stuff. Getting the timing perfect can be finicky though, and sometimes the game doesn't register it properly. If that happens, just reload your save and try the same spot again, usually fixes it right up.

The real payoff comes from finding all seven plants, which unlocks the full sasquatch character in director mode, giving you way more options to play with. Good to know while there's some bigfoot content in online mode, this particular easter egg only works in single player, so don't waste time trying to make it happen there. Just focus on hitting each daily spawn point under the right conditions, and you'll be stomping around as cryptid royalty in no time.