I used to guide for northern pike (amongst others). I was certainly used to the cuts, gouges and slices these toothy fish can dish out, but one time I was taking a hook out of a big, healthy 42" fish when it wacked me in the thigh with its tail. Not sure if it was the angle or what, but it felt like someone hit me with a small baseball bat! My leg just about folded right there. I managed to finish what I was doing and release it unharmed back into the lake, but I walked funny for the rest of the day