Bikum Calus and his fellow worker Sparv worked at the forced labor camp of Port Tarkin on Phelarion. Here they harvested the explosive megonite moss for the owner Thalassa Tarkin. Sparv and Calus had come up with a plan to escape from Port Tarkin and smuggle off enough megonite moss to make a small fortune. Calus was an old friend of Han Solo and planned to have the smuggler pick them and their shipment up. Princess Leia Organa whose Gossamer glider crash landed on Phelarion followed them into the labor camp after watching them explode a bit of moss.
During dinner that night Leia overheard them talking about the stolen moss and followed them as they left the mess hall. Sparv and Calus needed to figure out how to get to a transponder to get message to Han to pick them up. They caught Leia listening to their conversation and she told them she would be able to get to a transponder and send out their message. While Leia went to send the message Sparv and Calus went to check on the megonite. A stormtrooper walked by the cave with the megonite in it and they defeated him. Though they were now worried of more coming.
Darth Vader, Thalassa Tarkin, Leia and some Stormtroopers came to check on things. When they arrived, Leia started to escape with Sparv and Calus. They were seen escaping by Vader and he sent the stormtroopers after them. They were able to make their way to the end of the cave and take an elevator up to the surface where Han Solo picked the three of them up.
- Princess Leia, Imperial Servant (First appearance, as Calus)
- "ComicScan: Coming Full Circle"—Star Wars Galaxy Collector 3 (as Calus Bing)
- Star Wars: The Comics Companion
- The Essential Atlas (First identified as Bikum)