Tonic the Hedgehog is a false identity assumed by Metamorphia in the Issue 52 story, Face From The Past. Metamorphia's Tonic appearance looks identical to Sonic before he got his powers, which was fitting since Tonic was supposedly Sonic's long-lost twin brother. Hiding amongst a Trooper prison convoy, "Tonic" was rescued by the Freedom Fighters. Claiming to be Sonic's brother, he asked to join them, but Sonic knew for certain that he had no family to speak of and refused to accept the imposter. Tonic then ran off into the jungle where he secretly made contact with Dr. Robotnik to inform him of the plan's progression. Tails had followed Tonic and overheard him talking to Robotnik, prompting Metamorphia to drop her disguise. Before she could kill Tails, the other Freedom Fighters intervened and thus spoiled Metamorphia's divide-and-conquer strategy. Metamorphia fought the heroes but was outmatched, and so threw herself over a waterfall and escaped.