I bet I know who will think he is real... lol but no, there is not a "big foot" A species of his size and "popularity" would never be able to go unnoticed especially with the so called big foot hunters. There is a reason why there is never a clear, legitimate picture of one. I know nothing about big foot lore because I like to think about real, useful things but I would assume the believers think there is a species rather than an individual because the first "sighting" (from a quick google search) happened in 1811, no primate species can live this long even under ideal conditions with proper medical care. So the believers actually think that a whole population of these homonid creatures live here and somehow manage to evade detection with people actually pursuing them, which is completely absurd. Then there's always the "well new species are always being found so maybe he will be too!" This applies to species in obscure locations (under ice shelfs, deep in rain forests, deep oceans etc) and MOST of the time in this day and age if a completely new species is discovered it is very small (a bug, frog, etc). Or if it is a larger animal it is a small deviation from an already known species that native people or misinformed people wrongly identify, a giant hairy ape living in N America wont fit any of these scenarios of common new species discovery only adding to the substantial probability that he does not exist and is purely a legend for the naive/ bored lol
