The Spotted Monster Fish

Fishing along a small creek that runs into Clear Creek... I had cast a couple times when I saw this HUGE fish.  I thought is was a turtle.  It was spotted.  It opened its mouth for my clouser and then pulled back... or I pulled back.  I was fishing for perch!  I keep seeing that monstrous fish come out of nowhere in that small pool.  I start questioning myself later, "Did I really see that?" - a spotted monster fish.  After some digging, I think it may be real.