Orthrus

Orthrus was a duplicate of K-9 created by Drake.

Biography
Orthrus was created by Drake to frame K-9 so he could dismantle him. It took "50'000 man hours" to create him. In his first task he appeared when June Turner was making a statement to protesters about Department Microchips. When they started throwing fruit Drake angrily ordered the CCPCs to arrest them, Orthrus suddenly appeared and opened fire on the Department's banners and Balloons he then shot Drake. Drake then issued a warrant for K-9's arrest. When K-9 said he had no memory of the attack Professor Gryffen put a device on K-9's tail to see if he went "walkabout" during the next night. During that night Orthrus went into the mansion and severely damaged Mariah, A sentient Car owned by Gryffen and whom Darius Pike (Who Drake asked to join Drake) had a strong connection with. Darius was furious with K-9 and Drake with two CCPCs came to arrest K-9. Despite what he thought K-9 done Darius attacked a CCPC and ran with K-9,Starkey and Jorjie. When they split up Darius was alone with K-9 (actually Orthrus), he noticed him acting oddly and ran when he opened fire on him. He told Starkey and Jorjie of what just happened but they didn't believe him. When Orthrus came it armed its cannon at Jorjie, Starkey stepped in her way to protect her. When Orthrus prepared to fire he was fired at by the real K-9. Orthrus tried to attack K-9 but was disabled. When Drake came in and tried to arrest K-9, June Turner told Drake that Project Orthrus was not approved by Department and his plot was foiled.(K9TV: Jaws of Orthrus)

It's unknown what happened to Orthrus afterwards but it's likely it was dismantled

Technology
Orthrus had all the basic capabilities of K-9 such as Flying and a Photon Cannon. However since Orthrus was created using Department technology from 2050 and K-9 was created in the 51st century and became even more advanced after his regeneration it is likely that they are very different.

Behind the scenes
Despite the fact K-9 is voiced by John Leeson, Orthrus never spoke.