Update on Frog With 7 Legs

I was watching "The Most Extreme" Show on Animal Planet and I learned that there is a parasitic flat worm that attaches itself to tadpoles and cripples the frog as it grows so that it is easier for birds to catch and eat them. Flatworms complete their life cycle inside the bird's digestive tract, and the eggs are expelled with waste into the water. Some of the crippling effects on the frogs include the excessive growth of limbs.