After getting all chaos Emaralds Sonic never saw Eggman again but then Eggman made more robot and toke over all of the Zones it was up to Sonic but wait some little fox stopped him and said. He wanted to come Sonic asked if you can keep up and Sonic left but tails followed Sonic he could not keep up but he got up and used his two tails and followed Sonic and so that is how Talis became Sonic's Sidekick.
