Kaleesh masks, also known as Kaleesh war masks or Kaleesh battle helmets, were traditional masks worn by the legendary warriors of the Kaleesh native to the planet of Kalee in Wild Space. Frequently crafted from the skulls and bones of one of the fiercest and most fearsome animal species on their home planet—predatory beasts, mumuu, erkush, and karabbac—and smudged decorative lines above their eyes with Karabbac-blood war paint in battle.
Kaleesh masks, also known as Kaleesh war masks or Kaleesh battle helmets, were typically carved from the skulls and bones of one of the deadliest and most fearsome predatory creatures, mumuu, erkush, or karabbac, native to Kalee, known for their long eye openings, and if the light hits the mask at a specific angle, it is visible from a close distance. As with all Kaleesh masks, a set of six rows of those resembled karabbac's teeth and long, lateral slits that their slit-pupil golden eyes peered through dominating the masks and smeared with karabbac-blood warpaint lines above them upon entering battle.
The masks were traditionally worn by Kaleesh and were utilized in such battles, notably Kaleesh's war against their planetary neighbor, the Yam'rii of Huk. Apparently, if it were discovered that someone wore a mask like this just for effect, the Kaleesh would not tolerate it.
Decades before the Clone Wars, the infamous warlord Qymaen jai Sheelal, now known as Grievous, wore a mumuu-carved Kaleesh mask in battles, such as the Kaleesh's war against the Yam'rii, until one day he suffered terrible injuries in a sabotage shuttle crash that nearly killed him, destroying most of what remained of his original body. When Grievous became the General of the Confederacy of Independent Systems, he retained his homeworld's tradition and based his cybernetic mask after the one he had wore as a feared warrior and warlord.
During the conflict between the First Order and the Resistance, the Delphidian pirate Sidon Ithano wore a Kaleesh mask stolen from the Kaleesh, adopting one of their masks painted in a chosen red color to hide his heritage. At some point, Ithorian collector Dok-Ondar, owner of the store Dok-Ondar's Den of Antiquities, owned an original mumuu-carved Kaleesh mask worn by the late General Grievous.
Kaleesh masks were first mentioned in "The Crimson Corsair and the Lost Treasure of Count Dooku," a short story written by Landry Q. Walker, as part of the anthology Tales from a Galaxy Far, Far Away: Aliens: Volume I, and published on December 1, 2015 as an eBook, while first appearing in the Dok-Ondar's Den of Antiquities store at the Star Wars: Galaxy's Edge theme park, which opened to guests at Disneyland Park and Disney's Hollywood Studios in 2019.
The masks were originally introduced in the Star Wars Legends continuity, where it first appeared in "The Eyes of Revolution," a comic story written and illustrated by Warren Fu, published in the Dark Horse Comics anthology Star Wars: Visionaries, released on April 2, 2005, and first mentioned in the 2005 reference book Star Wars: Revenge of the Sith: The Visual Dictionary, which was written by James Luceno.