In "Lego Harry Potter: Years 1-4," you will have to battle a variety of foes. The game re-creates some of the most well-known scenes from the first four "Harry Potter" movies. You will encounter trolls, dementors and Harry's arch-enemy, Draco Malfoy. In year three, Harry and his friends encounter Malfoy in Hogsmeade. The meeting quickly turns into a battle, and you must defeat Malfoyin a snowball fight. You will use your wand instead of snow to fight back and beat Malfoy.
Dodge any small snowballs Malfoy throws at you. When he throws a large snowball, use the activate button to catch it. Use the joystick to aim and launch it back at him.
Repeat this process three times until Malfoy takes refuge in a snow cannon.
Use this same process to dismantle his snow cannon. Dodge the smaller snowballs to avoid injury. Use the activate button to catch the snowballs in midair with your wand. Use the joystick to throw the snowballs into the opening of the cannon.
Hit the cannon three times to dismantle it and end the battle.