"Maybe we should explore that in the movie sometime, the fact that Tails is immortal." That's almost consistent with the lore of the broader franchise, outside of the Game Gear version of Sonic 2 ...

Tails, who is Sonic's best-friend and sidekick, first appeared in 1992 with the release of the video game Sonic the Hedgehog 2. Tails is a yellow-orange, two-tailed fox whose 'real name' is Miles ...