Given the question: Generate a question that has the following answer: A boulder for the following movie plot: The short begins with Donald wiping the fog off his glass door, excited to see the snow. Donald says that he is excited about snow. He opens his door and soon gets his bill frozen from the cold. He gets a fur overcoat and pulls a sled, while singing Jingle Bells. When Donald reaches the top of the hill, he notices his nephews, Huey, Dewey, and Louie, at the bottom, building a snowman, while singing For He's a Jolly Good Fellow. Tempted, Donald crashes his sled into their snowman and thus his nephews, resulting each of them to "wear" a part of their snowman. While Donald is laughing himself silly, Huey, Dewey, and Louie plot revenge. The next scene shows Donald's nephews piling snow and a duck-like head on a boulder. Donald is scraping snow off of his foot when he hears his nephews yelling, "That's Uncle Donald! That's Uncle Donald! That's Uncle Donald!", while standing by the degrading snowman of Donald. "Oh, yeah?!" Donald replies, and he shortly crashes himself into the snowman-disguised boulder. The shockwaves from the crash shake off all of the furs on his overcoat, save for one, that Donald touches with his finger to stop its shaking and pulls out. Now Donald's nephews are laughing themselves silly and Donald pulls off the remains of his overcoat. He dashes off to start chasing them. Donald runs so fast, that he blows the snow off of a kissing couple. The nephews dash across a frozen pond to the center, where an imposing fortress made of ice and snow stands. Donald bounces off the mattress door that they throw up, causing him to ricochet across the ice (making a laser noise for each bounce) and crashing into a tree. Snow piles on top of him (with icicles around him) until he is "transformed" into a rhinoceros in a cage. As a victory song, the trio sings a verse of London Bridge while spinning and jumping in a circle. Donald bursts out of the cage, squawking angrily, and declares war on his nephews. Later on, Donald yells at his nephews from a snow battleship, that he created, while his nephews simply...
The answer is:
What is inside the mock-snowman?