AKA Agent Black Hound. The black sheep of the Puppy Family whose supposed actions caused his family to shun him and his place in the Puppy Family History Book to be taken out.

Luther Puppy lived in Victorian London and worked for the law force that would eventually become BUFF. The start to Luther's fall came when he desired to find Jack the Shredder who was terrorizing London and killing his fellow female agents. His boss, Charles Verminarty, told him to let it go and focus on his current missions but Luther wouldn't turn away from bringing in Jack to face justice for his crimes. Luther's mission to capture led him to discover a conspiracy led by Charles and an unknown woman to get rid of every agent and plunge London into a city wide crime wave. When Luthor confronted Charles about it, the boss had already pinned the murders on Luthor and made him known to every agent as Jack the Shredder. Luthor fought and shot Charles as vengeance (seeing justice as no longer an option) for the women he killed and Luthor was forced to flee the country to escape his comrades who now saw him as an infamous killer. But Luther's work wasn't done, with a handful of friends still in London he coordinated a mission to find the unknown woman who orchestrated this plot and stop her from causing more chaos and destruction. This woman would later be revealed as the Chameleoness, who disguises herself to look exactly like Charles and set the Victorian era BUFF on a dark path in the following years.