Prince Khor-Ru was the cousin of King Tut. After his death, he was mummified.
In Return of the Mummy, he's accidentally awakened by Gabe. During the confrontation with Gabe and Sari, Nila calls on her brother to kill the children, but the mummy walks right by them and instead starts choking his sister. "Let me rest in peace," the mummy groans as he assaults Nila. Gabe tries to break up the mummy murder and accidentally pulls off Nila's amulet. It crashes to the ground shattering into a thousand shards. She howls out and tells Gabe that the pendant was how she stayed alive all these years. At night she would revert into a scarab and climb inside the amber. Nila shrinks down into the scarab beetle and scurries away into the dark pyramid.
Prince Khor-Ru made an appearance among other Goosebumps monsters in the Goosebumps film; he is portrayed by Brian Gabriel, but credited as "Monster #8." He makes an appearance in the 2014 San Diego Comi-Con where Slappy refers to him as "the Mummy." He is one of the least seen monsters in the film. However, he receives a close-up when he is sucked back into a manuscript. His bandages are caught in the vortex, causing him to unravel as he is sucked in.
Prince Khor-Ru reappears in Goosebumps 2: Haunted Halloween; he is portrayed by Benjamin Bladon, but credited as "Royal Mummy". In Haunted Halloween, he is a Goosebumps-themed costume brought to life by Slappy.