Complex sentence: Skelton's voice pattern for Clem wassimilar to the later cartoon character, Bullwinkle; there was enough similarity to cause Skelton to contemplate filing a lawsuit against Bill Scott, who voiced the cartoon moose.
Split into simpler sentences: Skelton's voice pattern for Clem was very much like that of the later cartoon character, Bullwinkle. They were sufficiently similar to cause Skelton to contemplate filing a lawsuit against Bill Scott, who voiced the cartoon moose.