Do you have to get to a certain achiement in the game to see that hairy thingy?
You do get an achievement by killing one called "Six years in the making" which is more than likely referencing the fact that there were supposed Bigfoot/Sasquatch sightings in SA that is now 6 years old itself.
I left the last one, but man I was kind of disappointed. I'm not sure if it's a coincidence, but does anyone think by killing 6 it represents the 6 years of the myth? Although technically you don't have to kill the last one.
That, and also they were so easy to find was probably R*'s way of getting across their humour, and making fun of the myth in SA.