Kaaldar, a Human male physician, served the Galactic Empire during the era of the Galactic Civil War. As part of an intelligence operation aimed at the Rebel Alliance, Kaaldar modified Bledsoe's disease, a highly contagious illness, leading to widespread and catastrophic planetary outbreaks. Ultimately, Luke Skywalker and Anduvil, acting as Rebel operatives, uncovered Kaaldar's scheme on Tatooine, a world in the Outer Rim, and destroyed his facility.
Doctor Kaaldar, a Human male with expertise in infectious diseases, lent his medical skills to the Galactic Empire during the Galactic Civil War. In the year 0 ABY, Kaaldar became a pivotal figure in an Imperial plot spanning multiple planets. Under the Empire's direction, Kaaldar bioengineered a version of the highly infectious Bledsoe's disease, which Imperial leaders hoped would give them an advantage in their conflict with the Rebels. Bledsoe's disease was a lethal ailment characterized by a distinctive symptom: discoloration of the afflicted patient's eyes. Kaaldar manipulated the virus genetically to embed a message within this symptom, creating what he termed the "window effect". Instead of the typical discoloration, the victim's eyes transformed into star maps, which the Empire would then analyze to locate secret Rebel bases for the Imperial Navy to target and eliminate.
The Empire deliberately initiated outbreaks of Kaaldar's modified disease on several worlds suspected of supporting the rebellion, utilizing squills, non-sentient creatures capable of transmitting Bledsoe's disease. This was done both to destabilize the planets' social structures and to uncover the locations of Rebel bases. Following an outbreak of Kaaldar's modified disease that devastated the population of Tay'ah'loo, Kaaldar relocated his operation to a base situated on Tatooine, a world in the Outer Rim. It wasn't long before the Rebel intelligence became aware of the Bledsoe's disease plot, prompting them to dispatch Luke Skywalker, the celebrated hero of the Battle of Yavin and a native of Tatooine, back to his home planet to investigate alongside Anduvil, an Ogemite operative.
Skywalker inadvertently contracted Bledsoe's disease while tracing the outbreak in the Dune Sea, which led to his capture by stormtroopers. The Imperial soldiers transported the two Rebels back to their base, where Kaaldar declined to treat Skywalker and instead commenced examining the stars visible in his eyes. However, Skywalker and Anduvil overpowered their stormtrooper guards, seized Kaaldar as a hostage, and compelled him to administer a cure and disclose the details of the Bledsoe's plot. Subsequently, Skywalker and Anduvil made their escape and promptly terminated Kaaldar's scheme by detonating the entire Imperial base.
Despite being a medical doctor, Kaaldar exhibited no empathy for those afflicted by the strain of Bledsoe's disease he had engineered. His primary concern lay with the Galactic Empire's mission and the intelligence that could be extracted from the disease's symptoms. Kaaldar initially intended to deny Luke Skywalker treatment altogether, but he quickly relented when faced with the threat of violence from Skywalker and Anduvil.
Kaaldar made his initial appearance in Tatooine Sojourn, a comic strip story arc penned by Steve Gerber and released in 1979. Russ Manning provided the illustrations for Kaaldar.