Like many crime lords of his kind, Ka'Pa employed numerous Gamorrean guards and posted them throughout his throne room. He also had a protocol droid handy, which was common for Hutts.
During the waning days of the Old Republic, Ka'Pa owned a Twi'lek dancing girl named B'inka Fibuna. She escaped his clutches, earning a live bounty on her head, which was eventually claimed by Jango Fett.
Ka'Pa was involved in several criminal activities such as slavery, spice trading, and arms dealing. After the death of Jabba the Hutt by Luke Skywalker and company, Ka'Pa mistrusted the New Jedi Order, but established a business relationship with the New Republic—one of the only Hutts to do so.
Ka'Pa was offered amnesty by the New Republic in exchange for supplying them with resources. Mara Jade was sent to negotiate; however, due to Ka'Pa's prejudice against the Jedi, she was denied entrance and had to break into his palace and "negotiate" by force.
Ka'Pa confronted by Mara Jade
Ka'Pa asked her to bring him back Takara's Global Communications Transponder device in order to help the Republic. After Mara succeeded and gave the device to Ka'Pa, the Hutt offered the supplies as a gift, in return for Mara's silence: the device was illegal, and Mara, being an honest Jedi, would have had to report its exsistence to Mon Mothma.
Ka'Pa maintained contact with Mara Jade as well as Kyle Katarn, who had been a longtime contact of Ka'Pa's, both of whom served as the Hutt's liaison with the New Republic.
Ka'Pa was somewhat of a celebrity, because Riccix's Revised Basic Holodictionary featured an image of him in the entry on Hutts. The image was taken by the famous holographer Bovit Leebo, who was soon killed by Ka'Pa. When Leebo died, the image fell into the public domain, and was quickly snatched up by the editors at Riccix.
Ka'Pa the Hutt was voiced by Roger Jackson. According to Ryan Kaufman, Ka'Pa was created as an original character because the stories of the Hutts already in the continuity "were a bit muddy and hard to pin down." His Huttese dialogue was specially written by Ben Burtt.