Dogs are our friendly, lovable best friends. They don’t want to hurt anyone! So how do movies get dogs to attack people? With visual effects. A special effects team basically creates a digital double of a real dog, and then makes the CG-created dog attack the actor the way that the movie wants. In this VFX reel of German movie Look Who’s Back, it shows how that whole process works.
Bonus points: you get to see Hitler pretend a dog is biting his leg.