Two mermaids and a kitten.
No art without humor.
A mermaid who was heterozygous for hair color (= Gg, green) and who had normal fingers (= ff, mermaids with recessive traits must be homozygous for the recessive allele) had a father with blue hair (= gg) and webbed fingers (= Ff, since daughter is homozygous for the recessive normal fingers allele f) and a mother with green hair (= Gg or GG) and webbed fingers (= Ff).