Checkbox
Checkbox was a clone trooper serving the Grand Army of the Republic during the Clone Wars. He was stationed on the Arquitens-class light cruiser known as the Stellar Rise. During the conflict, General Grievous, representing the Confederacy of Independent Systems, infiltrated the cruiser. Upon revealing himself, Grievous promptly killed Checkbox.
Biography

Checkbox, a human clone trooper in the Grand Army of the Galactic Republic, got his designation as a nickname. He was born on the planet Kamino through cloning from the bounty hunter Jango Fett. The Clone Wars, a conflict against the Confederacy of Independent Systems spanning from 22 BBY to 19 BBY, saw Checkbox assigned to the Stellar Rise, an Arquitens-class light cruiser.
While he was taking stock of some crates that had been acquired from a stop near the Kazlin system, he noticed something strange about them. From the closest box, he could hear a noise similar to a stone mite. As the clone listened more closely to the noise, a blue lightsaber appeared, wielded by Separatist General Grievous, and hacked Checkbox in half vertically. Grievous had infiltrated the Stellar Rise to locate High Republic–era artifacts, accompanied by several IG-100 MagnaGuards. Two other clones, fellow soldiers of Checkbox, went to investigate his absence and were subsequently killed by the MagnaGuards.
Equipment
Similar to other clone troopers, Checkbox had a behavioral modification biochip implanted by Kaminoan scientists at the time of his creation. This ensured obedience to specific orders. Checkbox wore a standard issue clone trooper helmet.
Behind the scenes
Checkbox's character was conceived for "Galactic Tales: Saber Truth," the second story in the Galactic Tales short story series. Richard Dinnick authored the story, which was published in Star Wars Insider's 210th issue on May 3, 2022.