In the 'sakura kills gator fanfiction', it could be that Sakura has a very good reason for killing the gator. For example, if it's set in a fantasy world, the gator might be a menacing beast that has been terrorizing the local area or has some sort of connection to an evil force. Sakura, being a heroic or determined character, decides to take matters into her own hands and end the threat posed by the gator. But again, this is just one possible scenario based on the title alone.