Doppel-Moppel

Four animals (lion, bear, kangaroo and penguin) each comes in 6-fold. At first cursory glance, they all look the same and you have to look closely to see that the lion has swapped its crown for sunglasses. Only two animals of each species are really identical and those are the ones to find. But to do this, you can't just look at the animal discs, you have to rearrange the piles of discs according to precisely specified rules. —user summary