"Robofox" is the title of the Sonic the Hedgehog story that features in Sonic the Comic Issue #2, but may also refer to the state of the character Tails in that same story.
"Robofox" refers to Miles "Tails" Prower when he was turned into a Badnik by Dr. Robotnik. While Tails did not have his entire body encased in a Badnik shell like most of Robotnik's victims, he was subjected to mental programming and had mechanical armour attached to much of his body. In this state, Tails served Robotnik obediently and was ordered to destroy his friend Sonic the Hedgehog. Tails attacked Sonic in the Green Hill Zone, saying that he hated Sonic for leaving him behind to go adventuring by himself. His words were all a result of the doctor's mind control, however, which Tails began to resist as he watched Robotnik attack Sonic in his Egg-O-Matic. As Robotnik was about to deal the killing blow to Sonic, Tails threw himself at the Egg-O-Matic and destroyed its wrecking ball, as well as his own Badnik exoskeleton.
Though Robotnik has made other attempts to turn Tails into a Badnik, they have all ended in failure.