Hardcase was a clone trooper that appeared in multiple episodes of Star Wars: The Clone Wars, most notably in Season 5's Umbara arc. He was a member of the Republic Army's 501st Legion, serving under Captain Rex. Though a loyal clone, Hardcase was known to be hyperactive and enjoyed violence. He also had a tendency to disobey orders if he disagreed with them, though he always managed to get the job done. Like all of the clone troopers in the series, he was voiced by Dee Bradley Baker.
During the Republic's invasion of the Separatist world Umbara, Anakin Skywalker was called back to Coruscant to meet with Supreme Chancellor Palpatine. Taking his place as commander of Rex's platoon was Jedi Master Pong Krell, who had a very different style of leadership to Skywalker. Krell demanded absolute obedience from his clone troops and did not care for their concerns or opinions regarding his decisions, no matter how justified they were. Many of the clones, including Hardcase, grew to despise Krell over the course of the Umbaran campaign as the Jedi General ordered them to march into seemingly suicidal situations with no regard for their well-being.
After capturing an Umbaran airbase, Krell's battalion prepared a plan to march on the planet's capital, a plan that some of the clones believed to be reckless and foolhardy. Behind the general's back, Hardcase, Fives and Jesse devised their own plan to cut off enemy supply lines by infiltrating an destroying a Separatist supply ship in low orbit. Using captured Umbaran fighters, Hardcase, Fives and Jesse took off against orders and headed for the Separatist support vessel. They succeeded in boarding via the main hangar, but the way to the main reactor was blocked by ray-shields that their weapons couldn't penetrate.
While Jesse and Fives kept the Separatist battle droids busy, Hardcase exited his fighter and removed one of the missile pods, dragging it through a side door into the reactor chamber. After yelling to his comrades to get clear, Hardcase pushed the missile pod into a reactor junction and set it off, causing a chain of explosions that destroyed the ship and sacrificing himself in the process. Jesse and Fives managed to escape before the ship's destruction.