[TheLostPilgrim]

Apparently, in the Hobbit film, Radagast literally has a bird's nest in his hair and his beard and hair are covered in bird droppings.

''He is wearing a funnily-shaped hat with dominant brown and black hues, underneath which is revealed a bird’s nest with hatchlings making a mess all in his hair and beard! McCoy brings a disarming, childlike quality to the character. . . ''

"Sylvester McCoy as Radagast the Brown credits costume and make-up with helping him develop his character. His dormouse-like wizard (with animals running in and out of his beard) has a bird’s nest on his head. He said: ‘The birds don’t like to mess their nest so they stick their bottoms out and poo down my face.’

Also, in a drastic change from the source material, Radagast is the first wizard to visit Dol Guldur and discover that an evil power has established itself there. Later, Saruman makes slighting references to Radagast during a meeting with Gandalf and Galadriel. He accuses the Brown Wizard of indulging in mushrooms and dismisses the notion that the evil power Radagast has discovered could be Sauron.

"at one point, the wizard Saruman scathingly says of Sylvester McCoy’s character Radagast that “mushrooms have addled his brain”

He also has a pet hedgehog named Sebastian.