Just to nit pick, you are referring to 4 LOM not Zuckuss, 4 LOM is the robot and Zuckuss is a Gand, Kenner confused the names with the action figures.
In EU 4 LOM and Zuckuss felt that capturing the rebels leaving Hoth would be profitable rather than chase the Millennium Falcon so took out a transport, subsequent to the story 4 LOM and Zuckuss join the rebels on a promise that Zuckuss whose lungs were burnt by breathing oxygen (Gand breath ammonia not oxygen) , would receive medical attention. Tales of the Bounty Hunters is the book.
Good spotting though, at a quick glance it looks like a TIE pilot on the left of screen, it's not of course.