A nickname for the biggest whore one knows. Just like Tyrannosaurus rex means "King of the terrible lizards", Skankasaurus rex means "Queen of the skanky-ass sluts".
Guy 1: Dude, I think I can get an easy fuck from Tanya at the party...
Guy 2: Man, for your own good, stay away from her infested ass! She's such a Skankasaurus rex!
This is a female who is a skank, but you still want to hit that. She is defined as a skank who is kind of fly (fantastic).
Yo dog, let's leave this club. They ain't no ho's up here that I want to hit. Oh wait, that one over on the pole is skanktastic and so is the other one dancing in the cage! My bad.
The state in which a person, commonly a woman, exhibits extreme and uncontrolable slutty behavior, has a generally unpleasant demeanor, and/or who never shuts their mouth.
After I found out what Jess did after the party with that guy, and then bitched at her friend for doing the same with another young man, I have come to the conclusion that she is a skankasaurus.