Beavers are incredible creatures and significant ecosystem manipulators, but they’ve also been subject to various written and illustrative inaccuracies. Medieval bestiaries often depict the common beaver as a weird-looking dog that bites off its own testicles when pursued by mounted hunters. In this episode of Stuff to Blow Your Mind, Rob and Joe explore the meaning of these inaccuracies as well as the actual biological wonder of North American and Eurasian beavers.