T-Pup

T-Pup is a small, fox-like robot created by Tails while on Cocoa Island. It acts much like a household dog, panting with its tongue held out, yipping and even seen sleeping at the foot of Tails's bed. It understands Tails's commands perfectly and is capable of flight via a propeller that comes out of its back. Hours after T-Pup's creation, the Battle Bird Armada assaulted Antoine and Bunnie D'Coolette and Tails and his new pet tried to fend them off and help the couple and witnessed as Tails fought Speedy and was thrown to the ground by him. T-Pup then bit Speedy's tail from behind, following Tails as the two attempted to escape from their foe.

They flew upwards to an opening and lost Speedy by hiding between two rock structures sticking out of the cave's walls. Tails then ordered T-Pup to keep watch while he had some sleep, deciding he could make a better plan in the morning with some rest. When morning came, T-Pup woke Tails with an alarm, and the fox boy inadvertently knocked him off the ledge, though T-pup was able to save himself thanks to his propellers. The two then returned to the Sea Fox, only to find it surrounded by Battle Birds. But Tails's gas bombs soon ended that problem.

Another occurred underwater while searching for a secret entrance when Battle Birds in submarines showed up. They too were easily defeated, though damage had been taken and they needed to surface. This was fortunate for Antoine, as it allowed him a safe landing from up above. After explaining that Bunnie was undercover and enquring about the "strange little thing" that was T-Pup, Antoine said that must get back to the Battle Bird base, and Tails provided them a way back on to land. T-Pup then started scanning for the nearest cavern entrance to sneak into the Armada's underground base, and quickly led Tails and Antoine to it. T-Pup then used his eye lights to guide them through the caves and locate two Battle Birds armed with explosives, who they ambushed and relieved of their bombs (some stored in T-Pup for later usage) to blow a faster way to the base. This led to a confrontation with more Battle Birds, but help arrived in the form of Bunnie, who took a shine to T-Pup and started petting and fussing over him, until she got spooked by his holographic projectors, which showed the structurual information of the base she'd stolen. The four of them swept through the Battle Bird defences to the base, where they came face-to-face with Dr. Fukurokov and his Mole Mech, who quickly had them all on the ropes. The four then regrouped after Bunnie stunned the Mole Mech and Tails ordered Bunnie and Antoine to tear up the two points of the lab he'd shown earlier while he and T-Pup took on the Mole Mech using the bombs he stored in T-Pup. Using T-Pup as a distraction, Tails was able to loosen the parts connecting the Mole Mech together until all he had to do was hit it for it to fall apart. T-Pup's paw became damaged in the battle, however, and Tails had to carry him when the island started to shake. They went below ground and thought the island was sinking when really is was seperating from the land below as it was really the Battle Bird Armada's Battle Fortress. The four of them escaped safely and returned to Tails's cabin, where he fixed T-Pup's paw before they all had a "real" vacation.

After the split up of the Knothole Freedom Fighters, T-pup becomes a member of Team Fighters alongside Sonic, Tails and Amy Rose. He helped liberate Furville from Doctor Eggman. T-Pup was also present during Team Fighters trip to the Wolf Pack Nation.