Do you know what. I'm going to nominate one of my own designs for having a tragic 18th hole.
The caveat is that it isn't my fault!
The Plage des Nations course, near Rabat, in Morocco 'finished' with a spectacular, uphill par 5. That was until the owners couldn't secure the land on which Holes 11-13 are meant to be built. So, after the 10th hole, you get in the cart for a 1,350-yard hike to a temporary tee halfway down the 13th fairway.
To get the course up to 18 holes, the Moroccan operators, in their infinite wisdom, have shoehorned in a 70-yard downhill par 3 that plays from the end of the driving range tee to the chipping green. It is so short you can underarm a throw onto the green.
Bizarre and crap.