I am going to do a little prediction here - walnut comb. Rose comb from the Wyandotte mixed with pea comb from the Ameraucana.
Makes selecting Pea comb quite a bit more difficult I would presume at least at hatch.
not as hard as I thought it would be the pea comb actually stands out more then the other two being that I discovered rose and cushion combs seem to develop a little slower then the pea comb.