Name an animal with counter shadings

Countershading is a type of camouflage where the upper side is darker, and the lower side is lighter.  

The Grey Squirrel with its dark coat on its back and its pale belly is a good example of countershading in nature.

Many sharks also feature counter shading, being a dark color on top and having pale undersides.

Some counter shaded animal would be a dolphin and a certain type of fish.

I'm not sure about about a, but b should be parasite