When the booty on a female is too big to be true. So big and perfectly shaped, no one will ever believe you. That's when you know it's ok to use the term Donkasaurus Rex.
The drunkperson in your neighborhood known for doing yardward with a beer in one hand and lawnmower in the other; Also known for walking his dog while drinking beer;
Look! Drunkasaurus Rex is using the hedge trimmers! Better call 911 now!