The South Dakota Division of Fish and Wildlife was wanting to develop a faster-growing, larger walleye hybrid. After much contemplation, they crossed walleyes with Coho salmon. The cross was called a Co-Wall. It grew quickly to good size, but was rather docile, even by walleye standards, so they looked for a third cross with a more aggressive fish. They settled on muskies. The result was called a Co-Wall-Skie. They were of impressive size and aggression, but they had to teach each one of them to swim.
