In 1967, Roger Patterson and Robert Gimlin entered the woods of Northern California with the goal of filming Bigfoot. Lucky them: they apparently did.

The Patterson-Gimlin film, showing either a North American anthropoid ape unknown to science or a dude in a monkey suit, is probably the single most analyzed piece of "home video" footage outside of the Zapruder film. Hundreds of experts in biology, zoology and costume design have chimed in on the topic, but cryptozoology-themed YouTube channel Crash Course Cryptozoology brought in a new expert: fursuit maker Chloe Fraser.

The video has never been conclusively debunked; though the fact that in the half-century since it was filmed, nobody else has gotten anywhere near the same amount of luck with Bigfoot (and/or Sasquatch) as Patterson and Gimlin has been gotten it a status of "debunked by default" by sceptics. Even if you're a Bigfoot believer, and they really are out there wandering the woods, it doesn't necessarily prove the footage isn't fake.

Patterson's goal was profit-driven, and he did make money from the footage, which does give a motive for faking the film. However, neither he nor Gimlin ever confessed to a hoax, unlike many other famous cryptozoological hoaxes. Multiple people have come forward claiming they were in the suit, but as they can't all be telling the truth, most of these claims are also "debunked by default".

Anatomists have pointed out that features of the animal shown don't really make sense. Its large, domed head, like a gorilla, would suggest a diet of vegetation, with the dome being the anchor for strong jaw muscles necessary to chew this diet; but it lacks a gorilla's "pot belly", which is required to digest this diet. For a more furry anatomist critique, the creature is female, with noticeable fur-covered breasts – which, while common in furry art, is rare in nature, as infants would wind up with a mouthful of their mother's fur in real life.

Though fursuit builder Fraser ultimately says it's possible that it's a suit (while finding it unlikely), most professional special-effects suit makers seem to agree it's fake. There was a long-standing rumor that the suit was created by John Chambers, who created the apes for the original Planet of the Apes movies… though this is yet another "debunked by default" urban legend, as it seems unlikely Patterson would have had any contact with Chambers.

Many professional costumers have gone on record saying that not only is the creature a man in costume, it's not even a very good one, and they would not do it that way themselves. Though, given that the footage is still having people ask if it's real half a century later, maybe they should?