You can get a modified single comb from a silkie cross. I have two silkie cross cockerels - the first one (1/2 silkie) started with a walnut comb that has morphed in to a walnut with horns at the top. The other silkie cross cockerel has 4 toes on each foot, and a single comb - he's not old enough to have much of a comb yet, so right now it looks fairly "normal". He's actually 1/4 silkie, and has about the same amount of foot feathering as the bird posted.