Treble is a robotic wolf created by Dr. Wily as a support unit for Bass, similar to the relationship between Rush and Mega Man. He and his master were employed by Wily and Dr. Eggman during their united effort to take over both Mobius and Earth 20XX.
In the altered reality created by the second Genesis Wave, Treble and Bass had been created and had clashed at various times with Mega Man. The two were incorporated into Dr. Wily and Dr. Eggman's combined forces in the Skull Egg Zone, and were stationed aboard the Wily Egg. Treble apparently remained on board the Wily Egg for much of the conflict, and grew to dislike Orbot and Cubot, Eggman's mechanical lackeys who were charged with watching him. He was later deployed alongside his master and Metal Sonic v3.0 to challenge Mega Man and Sonic the Hedgehog, who had boarded the flying fortress to challenge the doctors. Treble proved a formidable foe, attacking both Mega Man and Sonic with his speed, claws, and teeth. However, he sustained a great deal of damage during the fight as both heroes attack him, Sonic with his Spin-Dash attack and Mega Man using his Mega Buster and the weapons of the Roboticized Masters. In the end, his back right leg was injured to the point of uselessness, taking him out of the battle. He did manage to serve as a crutch of sorts for Bass, who was too damaged for the two of them to fuse together as was their ability. The pair subsequently watched as the heroes were defeated and captured by the Egg-Wily Machine X, and were shortly thereafter enveloped by the Super Genesis Wave. However, their world was then restored to normal by Super Mega Man, and the pair were apparently returned to their proper place in time. (StH: #250, #251, MM: #27, SU: #54)
Completely loyal to Bass, Treble is also savage, attacking his enemies with great ferocity. The only compassion he seems to harbor is towards his master, and Treble seems to be the only being whom Bass truly cares for as well.
As a robotic wolf, Treble possesses great strength and speed, and is armed with sharp claws and teeth. He also possesses the ability to fuse together with Bass just as Rush can with Mega Man, though the villains did not demonstrate this ability in their battle with Mega Man and Sonic.
- Like many Mega Man characters, Treble's name has a musical theme.
Treble is mostly covered in purple armor, though his exposed face is white with red eyes and he sports a pair of ears that stick out from his large, cone-shaped helmet. His clawed feet are also white, while his legs are purple and connected to shoulders and hips that resemble black circles in gold frames. His body is composed of two ovoid components, linked by his "waist" and by a pair of cables that hook from one section to the other. He also has a tail that resembles one of these coils with a large cylinder on the end. Treble's legs each bear two gold fins, with their points facing upwards.