My campaign world features "The Great White Bulette" The creature's domain is a large land areas just west of the main campaign areas most of my campaigns start in.
The Great White Bulette is advanced to the largest dice and size for its monster class and is easily identified by its dirty white color. This bulette was put in my campaign world some 20 or so years ago and has managed to survive to this day. I have since given it the Monster of Legend template.
The creature has taken on legendary status amongst my players. Originally, I put it in my campaign as a challenge for the party but it soundly trashed that group of would be heroes. In a follow up campaign, another group of characters tried to make a name of themselves by trying to end the scourge of the Great White Bulette and got devoured to a man.
In another campaign, the characters once again tried to hunt it down (it was notorious for eating entire caravans unlucky enough to get caught passing through its hunting grounds) and when they spotted an adult red dragon "get taken" in mid air by the Great White erupting out of the ground (the dragon was flying low to get some herd animals), the party changed their minds and left.
Over the years, every now and then, a party of adventurers tried to make a name for themselves by hunting the bulette and ends up on the losing end.
Nowadays, my groups will take 8 days to go around the Great White's known hunting grounds to go to destinations in the west rather than risk the three days it would take to cross the Great White's domain.
Now, that's satisfaction!