Just to add to Del's Point

YouTube - "Butter Daddy" footage

Platty/Daddy/Butter are all on the same allele so only one gets passed on. So if you breed a platty daddy to a normal you get all 'Daddys' (normal looking snake) and lessers. You know all the normals have to be 'Daddys' because otherwise they would be lessers as the snake has to pass on at least one of the genes (lesser or daddy). So breeding a lesser to a 'Daddy' you get Platty's, lesser's and daddy's (only half the normals will be daddy).