I have had them(tiger muskies,in my case) on two different occasions and they ignored anything that wasn't alive.Perhaps they could eventually have been broken and converted but they would not even move when I dropped in raw foods.I had a walleye on frozen shrimp, of course different fish but similar nonetheless. I would imagine northern pike and muskie to be very similar in difficulty taking none live.
Awesome fish too, would be great to see them in a scaped tank.
There is a Cabellas hunting and camping,outdoors superstore not too far from me and the last time I was there they had a huge display tank with hundreds of foot long muskies in there.