Wild: Apparently they live somewhere on the beach. He can be attracted by a large concentrations of Dodo. I first encountered this creature while watching the hunting of another tribe. He suddenly appeared and attacked hunters. How could such a monster be born at all?
Domesticated: Good beast of burden, but too stupid. It seems the last who tried to tame this creatures was eaten.
The DodoRex is a fan-made dino for which also a fan-made dossier was created. However, Wildcard has announced that the DodoRex will make its appearance in the game on special events (like April 1st?). They even released an official document on the appearance of the DodoRex: