theories on how Bigfoot got on our planet

Gigantopithicus descendant. Some say that Bigfoot is just a relative to Gigantopithicus.

Relic hominid. Some say that Bigfoot is a elusive, surviving hominid

Alien exile or experiment. Some Bigfoot enthusiasts say that Bigfoot is a non-terrestrial experiment mad by aliens and was put on Earth.

Portals and orbs. Some say that Bigfoot is an interdimensional being that travels between dimensions, and that is how he escapes so easily.

Olly's personal theory. I think that there was this scientist, and he was playin' around with some dangerous fusion chemicals, so then he accidentally touched some, and then accidentally touched Gigantopithicus hair! Then he turned into, the legendary, the extraordinary, Sasquatch!