Why is evolution hiding?

[Esquilax]

Okay, so there are transitional fossils. Thank you for the link. I won't deny it to be true.

I see things comparable to a termite becoming a cockroach but not a fish becoming a mammal.

You gotta scroll down, man. There's a whole list there.

There are quite a few steps between fish and mammals though; Tiktaalik is a fish with legs, but what you're looking for is probably some of the Synapsid fossils, the "mammal-like reptiles" that evolved into mammals. They are there, though. That's the important point.