Yes, Kermit is real!
A new species of frog was recently discovered in Costa Rica, and yes, it does look like Kermit. The frog is a species of glass frog that has been named Hyalinobatrachium dianae. Since it is a glass frog, you can see through its underbelly!
To me, at least, this shows how many amazing animals can still remain "undiscovered" in our world.