GMS v146 - Return to Masteria

All these Bigfoot ideas are neat, but you gotta take into consideration that this is a lvl 90 area. It shouldn't be a mega tough boss to fight.

While that's true, it doesn't necessarily have to mean that should always be the case, or that Big Foot can't be crazy impossible. It's not really the same, since Empress is pretty out of the way, but take Future Hen/Ereve. Ostensibly, it's a level 160+ area, Empress herself is 190, and for a pretty long while, she was pretty impossible even at 190.

And going further back, there were also Iron Boars at Pig Beach and Jr. Boogies at the map with the Wild Boars. Much smaller scale, but they were pretty difficult to handle for people of the intended level range.