A hunter could be the main antagonist. Hunters are often seen as a threat in stories involving wild or unusual creatures. They might be after the werewolf for its pelt or just because they see it as a dangerous beast.
The plot might also involve the werewolf having some special power. Say it can control the elements when it's in its werewolf form. Alvin and the chipmunks see this power and are in awe. But then a villain, like an evil wizard, wants to capture the werewolf to use its power for bad things. Alvin, Simon, and Theodore must then use their musical talents and quick thinking to stop the wizard. They could perform a special song that has some sort of magical effect, like calming the wizard or breaking his spells, all while protecting the werewolf from being captured.
Theodore could also be the main character. He's the kind - hearted and a bit more timid one. If he were the main character in a werewolf fanfic, it could be about how he overcomes his fear of the werewolf. Maybe he has a special connection with the werewolf, like he realizes that the werewolf is not all bad and tries to befriend it, which would be a very different take compared to the others.
One possible plotline could be that one of the Chipmunks gets bitten by a werewolf. Then, they start to experience strange changes during the full moon. Their normally cute and friendly behavior turns more wild and unpredictable. Their friends notice the difference but at first think it's just a phase or that they are getting sick.
In a fanfic where Alvin is in prison in the 'Alvin and the Chipmunks' universe, it could be a really interesting take on his character. He might face challenges from other inmates who don't like his upbeat and sometimes mischievous nature. However, Alvin could also bring some positive change to the prison, like starting a music group among the inmates to pass the time and boost morale.
Obviously, Dracula would be the main antagonist. He is a vampire, after all, and his nature is to be somewhat menacing. He has powers like turning into a bat, hypnotizing, and super strength. All these things could pose a threat to Alvin and the Chipmunks.
One possible plot could be that Alvin and the Chipmunks are on a trip and accidentally end up in Dracula's castle. Dracula might initially see them as a source of entertainment or a new kind of prey. But as the story progresses, the Chipmunks' cute and innocent nature might start to change Dracula's view. He could become conflicted between his natural vampire instincts and his growing fondness for these little furry creatures.
One possible reason for Alvin's depression in a fanfic could be the pressure of constantly being in the spotlight. As the lead chipmunk, he always has to be on top of his game, whether it's performing or coming up with new ideas. This unending stress might lead him to feel down. For example, in a big concert coming up, he might feel like he's not good enough and start to doubt himself, which could be a start of his depressive state.
Maybe there's a competition in their town, like a battle of the bands. The Chipmunks and Chipettes have to work together to create a unique performance that showcases their individual talents as well as their ability to collaborate. They face challenges along the way, like a broken instrument or a member getting sick, but they overcome them with their friendship and determination.