USPS Frogs Forever First Class Postage Stamps

The northern leopard frog comes from the family of ranidae, which is the "true frog family."  This frog is a hardy breed and has become the state amphibian of Minnesota and Vermont.

The northern leopard frog is a medium-sized frog, measuring around 2-5 inches long.  It is green or brown with dark spots and can leap 5-6 feet in a zigzag pattern.  Since this frog doesn't secrete anything through it's skin, its color and ability to jump help it to escape predators.

This frog can also slow its heartbeat, which helps it survive winter when it hibernates on the bottom of ponds.  In spring, it emerges as if it never slowed down.  After the northern leopard frog mates, in March-June, it leaves the water and spends the summer in grassy areas.  It has a large mouth and eats the typical small insects, but has also been known to eat birds, gartern snakes, and even bats.

The northern leopard frog produces an enzyme in its oocyte (egg cell) that has been found to attack cancer cells.  This enzyme, called amphinase, can be extracted from the eggs and also can easily be made synthetically.  Researchers are optimistic the enzyme will be an alternative to invasive operation, radiation, or chemotherapy.  The northern leopard frog might just be the hero that makes cancer a non-life-threatening disease.