Hi Andry – no, there is no plugin that does this because it is a terrible idea. If you decide you want to, you can create multiple accounts but I cannot urge you strongly enough not to take this approach.
Ideally when you start your community you should already have a group of beta users or founding members who can create initial content while the community builds up momentum. Communities are about trust – if you are creating fake accounts to write content you are undermining the trust of your members and it will come back to bite you.
I’d recommend reading this resource (and the many other great ones on the same site).