When determining a character's motivation, ask yourself what the character is hoping to achieve by the end of the story. In Despicable Me, what is Gru's motivation? Is it to be the best villain or is it something more? (Hint: It's something more. Who does he want to impress?) Remember, you have to be able to provide proof of a character's motivation. This can be done by paying attention to the events of the story, then proving how these specific "events" show us the character's motivation.