Notes:

I'll just copy-paste the artist's description:

"I have a theory about Infinite from Sonic CD. He has always been in the Sonic series, we just didn't realize until now. The big clue is the symbol. We've seen that same symbol in Sonic CD. You've probably heard of the easter egg. You can see the same symbol in the picture. But it doesn't stop there because in Sonic 06 (Yes I CANNOT believe I'm mentioning this, but like it or not, we have to accept it's canon), "https://68.media.tumblr.com/e7a62a3d79920e69d602bf42f4a75392/tumblr_orp5dfQHNW1vjuh1lo1_500.png">Mephiles makes the same symbol.

Personally I think Mephiles the Dark, Infinite, and the creepy Sonic CD easter egg have a connection. Why is that? I believe it's because they're one and the same."