My unusual casting practice

This evening I went to the Green Lake (which is in the center of Seattle) to improve my casting techique a little bit.
There is a special fishing pier with targets installed underwater. I stringed my rod with new sinktip line and tied black marabou streamer. I started to cast and after third cast I snagged the bottom. But after pause I discovered that I hooked a fish(!). I saw long body with light spots and vertical bars. Wow!!! It was a little northern pike (or tiger muskie?)
Of course it was "little" for average pike but not for my trout rod with 5X leader! I used to spin fishing for bass and trout in lakes but never heard about muskies in Seattle's lakes.
I dragged a fish carefully to the shore to land it. When it was pretty close to me pike started to jump high and recklessly. And after several leaps he(she)'s gone with my fly in the mouth. What a disaster!!!!
I never thought I could catch a fish during my casting lessons and I never expected it can be a pike.