'The Simpsons' has had loads of amazing TV show crossovers over the last few decades, but did you spot this 'Reacher' parody ...

Crossovers are usually designed to feel seamless, with characters slipping into each other's worlds or tones aligning just enough to make the whole thing feel like a natural extension of both shows.

Of course, just looking at video games is only scratching the surface of Sonic's wild history of crossovers. Over in the world of comic books, Sonic has met up with Archie and the Riverdale gang, has ...