CH-33P, known as "Cheep," was an astromech droid of the C1-series line, possessing masculine programming, and he served the Galactic Republic throughout the Clone Wars. After the Siege of Mandalore, he, along with astromech companions R7-A7 and RG-G1, aided Ahsoka Tano, the former Jedi Padawan, in the aftermath of Order 66, when the Republic's clone troopers betrayed the Jedi. Cheep, along with G-G, met his end when he was destroyed by clones under mind control while assisting Tano and Clone Commander Rex in their escape from the Tribunal.
During the final days of the Clone Wars, Cheep found himself stationed on the Venator-class Star Destroyer Tribunal, which had been dispatched to Mandalore. Following the Siege of Mandalore, which resulted in the capture of the rogue Sith Lord Maul and the defeat of his Death Watch forces, the 332nd Company, accompanied by Ahsoka Tano, the former Jedi Padawan, returned to the Venator with Maul as their prisoner. Shortly thereafter, the starship jumped into hyperspace on its return journey to Coruscant.
After the execution of Order 66, Cheep, together with fellow astromech droids R7-A7 and RG-G1, consented to aid Tano after she sought their assistance, having narrowly avoided execution at the hands of Clone Commander Rex and his troops. The droid played a role in Tano's capture of Rex so that his inhibitor chip could be removed, helping G-G isolate him from his men by trapping him in an intersection using blast doors. Subsequently, R7 stunned Rex into unconsciousness after Tano revealed her presence. Cheep, G-G, and R7 then assisted in transporting Rex to the medical bay, where he underwent surgery.
To reach the hangar of the Star Destroyer, Ahsoka, Rex, and the droids had to battle their way out of the medical bay. Upon reaching the hangar's command center, Ahsoka instructed Cheep to ready a shuttle for their escape. Simultaneously, R7-A7 opened the doors to Bay 12, revealing a large contingent of clones, led by CT-5597 "Jesse," positioned near the Nu-class attack shuttle. While Ahsoka and Rex diverted the clones' attention by staging a fake capture of Ahsoka, the droids stealthily moved through the hangar behind them.
To assist Ahsoka and Rex in their fight against the clones, the droids lowered the platforms in the hangars before Maul entered the hangar, intending to seize the shuttle and escape. Maul managed to board the shuttle and exit through the bay doors, as Ahsoka was momentarily distracted after being pushed into the opening created by the lowered platforms. For a brief period, Ahsoka used the Force to hold the shuttle back, but she ultimately released it to focus on defending Rex. During her attempt to restrain the shuttle, R7-A7 was struck and destroyed by a blaster shot.
Following Maul's escape and the destruction of R7-A7, Cheep and G-G continued to manipulate the lifts in the hangar, enabling Ahsoka and Rex to reach a ship located in the lower deck. However, after raising the platforms, the clones discovered the two droids' location. Despite G-G and Cheep's attempts to surrender, the clones executed them.
Cheep was a C-series astromech droid with grey and yellow plating, standing at a height of 1.05 meters (3 feet, 5 inches). As with all C-series droids, Cheep featured three sensors and an antenna on his dome, along with two gripper arms and a computer interface arm. Cheep demonstrated loyalty, volunteering to assist Ahsoka Tano when she became a fugitive from the clone troopers following Order 66. Cheep was equipped with a mechanical right arm capable of discharging electricity. He also had the ability to pilot starfighters and perform starship maintenance, repairs, and information retrieval.
Cheep made his debut in the Star Wars: The Clone Wars episode "Shattered." Dave Filoni, the series producer, provided the droid's voice, and he also voiced another C-series droid, Chopper, in Star Wars Rebels.