There’s a deleted plot line from The Empire Strikes back involving the caves that the rebels have built their base out of. Part of the story was going to be that wampas – like the snow monster that Luke is captured by – live in the caves the rebels are building their base out of, so they’ve been working to seal them off.
The wampas in the caves storyline was deleted from the final cut of the movie, but we do have this gif from the cut scenes:
C-3PO removes a sign that’s warning about the dangerous monsters behind a door. The snow troopers, without benefit of the sign, open the door and are attacked by wampas! It’s a very Simpsons type of joke. Futurama had a great gag where the ship accidentally knocks down part of the Great Wall of China and an army of Mongolians immediately rides in to invade, as if they’ve been waiting there for thousands of years with only the wall to keep them back.
Aside: The movie’s pacing doesn’t linger on this, but the rebels have just finished setting this base up when the Empire finds them and they have to leave. It’s one of many minor world-building moments many people don’t see the first few times they watch it but I think it really heightens the straits the rebels find themselves in. They’ve been living on this cold, uninhabitable planet for months or years, they’re just barely gotten set up, and then they have to go back on the run.
This year Disney has been producing a series of short cartoons featuring some of the Star Wars female cast, called “Forces of Destiny.” I was amused to find this one, “Beasts of Echo Base,” that directly pulls from the deleted scene.
Here’s the full YouTube playlist of all the “Forces of Destiny” shorts. This breaks my rule of ignoring all but the original trilogy, the sequel trilogy, and (for now) the “Saga” spinoffs like Rogue One, but so be it.