The introduction of Metal Sonic in the third Sonic the Hedgehog movie could allude to another beloved character joining the ...

Sonic the Hedgehog 3 introduced Metal Sonic in a credits scene to set up the character as a Sonic 4 villain, but it created a major problem.

“Sonic and his friends have faced everything from mad scientists to ancient spirits ... with one particularly compelling scene showing Metal Sonic in the foreground while Batman looms overhead.