CH-33Z was a MSE-6 series repair droid. At one point, the Chadra-Fan Vosa stood atop the MSE series droid at the Day Star Hotel while she spoke to her spy, Faddey. In the era of the New Republic, CH-33Z was scurrying around the halls of the New Republic Correctional Transport Bothan-5 when he was shot and destroyed by Burg, a member of Ranzar Malk's crew of mercenaries who were there to rescue the prisoner Qin. CH-33Z's destruction alerted N5 sentry droids to the crew's presence.
CH-33Z with his appearance from The Mandalorian in The Star Wars Show.
CH-33Z "Cheeze" originated as a recurring side character on the online variety news show The Star Wars Show, interacting with the show's hosts as its resident sound expert and "mouse droid extraordinaire." He made his first appearance in the show's debut episode on May 11, 2016, though unnamed at the time, as his name was left up to fans to decide through social media. After receiving many humorous suggestions such as "Mon Mousema," "Mouse Eisley," "Mouse Windu," and "Mouse Kanata," hosts Peter Townley and Andi Gutierrez announced at the end of the show's second episode on May 18, 2016 that the mouse droid had officially been named "CH-33Z" or "Cheeze," based on the suggestion of Star Wars fan Colin Bishop (@storydroid) on Twitter.
CH-33Z is destroyed by Burg.
CH-33Z was introduced into Star Wars canon when he made a brief (and fatal) cameo appearance in "Chapter 6: The Prisoner," the sixth episode of The Mandalorian Season One, directed by Rick Famuyiwa and co-written by Famuyiwa and Christopher Yost and released on Disney+ on December 13, 2019. While unidentified in the episode itself, he was identified as CH-33Z in the January 2020 episode of The Star Wars Show, released on the Star Wars YouTube channel on January 29, 2020. The droid made another cameo in "Episode 4" of Star Wars: Jedi Temple Challenge, released on the Star Wars Kids YouTube channel on June 24, 2020.