What mammal builds nests underground lined with grass and dried vegetation?

Badger

Who plays Marty McFly's eccentric scientist friend in "Back to the Future"? Which bird is known for its enchanting tail feathers during courtship? What's the name of Link's primary sword in the 'Legend of Zelda' series? What is the main vegetable used in making pickles? In Doom (2016), what facility on Mars is overwhelmed by demonic forces?