Melina Carniss, a Human with dark hair, worked as a dance choreographer for Jabba Desilijic Tiure. She also secretly functioned as a security operative.
At Jabba Desilijic Tiure's palace located on the planet of Tatooine, Melina Carniss initially performed as a dancer before becoming a dance choreographer. In addition to her performance duties, she secretly served as a security officer within the palace. In 4 ABY, she attempted to apprehend Mara Jade, who was disguised as a dancer named Arica. This occurred when Jade attempted to seize a blaster from one of the palace guards. Carniss believed Jade was involved in an assassination plot against Jabba orchestrated by Lady Valarian, one of his rivals. However, Jade's true target was not to kill Jabba, but rather Luke Skywalker, who was scheduled to meet with the Hutt.
Carniss apprehended Jade and escorted her from the throne room towards the dungeons. As she handed Jade over to the Gamorrean guards, Jade employed the Force to redirect Carniss's blaster, causing her to inadvertently shoot one of the Gamorreans. Consequently, the guards attacked Carniss with their force pikes, allowing Jade to make her escape.
Two years following Jabba's death, smuggler chief Talon Karrde recruited her. However, she became a spy for Ysanne Isard during the Bacta War in 7 ABY. Carniss provided crucial information about a smuggling operation within the Alderaan system, which led to an ambush by Captain Ait Convarion's Star Destroyer, the Corrupter. Wedge Antilles's group successfully repelled the attack. Upon discovering her betrayal, Karrde initially intended to eliminate her immediately. However, Booster Terrik, with considerable effort and expense, convinced Karrde to spare her life. The plan was to use her to feed false information to Isard, ultimately setting the stage for the Battle of Thyferra. During the Bacta War, she captained the YT-1210 freighter Empress' Diadem, which sustained damage from turbolaser fire originating from the super star destroyer Lusankya while functioning as a missile platform during the final battle. After the Bacta War concluded, Karrde executed her.
Two years later, Karrde encountered a woman named Celina Marniss (an anagram of Melina Carniss), who was revealed to be Mara Jade. He hired her soon after he discovered this.
In Timothy Zahn's 1995 short story, "Sleight of Hand: The Tale of Mara Jade," the character Melina Carniss was depicted as a dark-haired woman wearing a red jumpsuit, crouching near the rancor pit after Oola was dropped in. This depiction was later changed, and the character in the red jumpsuit became Laudica. A Human female with black hair, wearing a white dress first appeared in the Special Edition release of Star Wars: Episode VI Return of the Jedi, but it is unconfirmed whether this character is Melina Carniss.
X-Wing: The Bacta War heavily suggested that Carniss perished when the Empress' Diadem was struck by fire from the Lusankya. The perspective from the Lusankya's bridge described the destruction of a disc-shaped Corellian freighter matching her description. However, The New Essential Guide to Characters contradicted this account.