I would tend to agree with Jeff as has produced a Daddy-- although "knowing" is doing -- and pairing has not been done to date.
I produced an animal in from a Butter x Normal pairing in 08 that I believe to be a Butter Daddy. He is breeding some girls -- normals and a couple morphs. Will take some time to prove him unless I get lucky and hit on a male non- Butter morph.I will be NO DOUBT be putting any male morph I get from him on a Butter girl when he is breeding ready!!!!!