In Animal Farm, Napoleon taking the litter of puppies away from their mother to raise them himself is an example of "foreshadowing."
Foreshadowing is a literary device in which a writer gives an advance hint of what is going to happen later in the story. Foreshadowing usually is presented at the beginning of a story, or a chapter, and it helps the reader have expectations about the future events. Foreshadowing may appear in the form of character dialogues, plot events, and changes in setting.