Yeah, Rancors were specifically what I was thinking of when I thought of EU reuse. Unless you count Sand Wampas as being an actually thing.
I think it's a pilllar of the Star Wars formula that's often unthought of.
TPM
Big Fish. Bigger Fish, Biggest Fish
AotC
Gladiator Rhino, Mountain Cat, etc..
RotS
Obi-Wan's feathered lizard mount?
Am I forgetting something?