My first guess? It's likely a reference to the scrapped subplot in ESB where a large group of wampas would attack Echo Base. Some of the wampas would apparently be captured, leading to a scene later where 3PO tears off a warning label on their door with unpleasant consequences for pursuing snowtroopers - this made it into an early trailer.
As I understood it, they weren't captured, the Rebels just sealed a blast door from a section they had opened out to barracks or whatever. The wampas had just infested it. It's sort of soft canon now, thanks to Forces of Destiny. Sent from my SM-G973U using Tapatalk
Well with the Cliff Wampas it explains why the Wampas were in pens/cages on Echo Base. In that storyline they were captured and incarcerated by the Rebels. Later it was the Empire that actually used many of those captured Wampas and/or captured their own to bioengineer the "Cliff Wampas" to serve the Empire as war beasts and guards.
Honestly, "weird video game poodoo that they jumped through hoops to make Actual Canon" is a subject that probably warrants its own thread.
Oh yes, I do remember the cliff wampas! I actually paid them a visit not too long ago. I always assumed they were indigenous to Gall, though. Or maybe a couple of wampas had been transported there for some reason, several generations back, and then evolved. It wouldn't exactly be the first time something like that happened in the GFFA.
