What is the counterpart to starch in animals?

The counterpart to starch in animals is glycogen. Glycogen is a highly branched polysaccharide that is the primary storage form of glucose in animals. It is found in the liver and skeletal muscle, and is broken down into glucose when the body needs energy. Glycogen is synthesized from glucose when blood sugar levels are high, and is broken down into glucose when blood sugar levels are low.