I've been fishing for wild trout for over 40 years and have caught a single tiger trout. It was from a very small first-order stream in the Laurel Highlands, that at the time I'd fished for 17 years and had only caught brook trout. I was shocked but later discovered the stream it flows into has a small population of reproducing browns well down stream explaining the source of the female parent.
It was an extremely aggressive fish. It took a dry fly, and I failed to set the hook. I barely rested the water, but it took the dry equally hard on the 2nd cast. It fought much harder than brook trout of the same size.