It doesn't exist because there is no proof that it lives. There are no genuine pictures, there haven't been mass views of it and if there was a monster of some sort, then it would be a major story on the news. And besides, spaghetti isn't even alive - it can't respire, reproduce, grow, it can't even move. Therefore, there is no proof that it actually exists. :P
By the way, this is a ridiculous question, and to be asking it would only be the behaviour of somebody aged under 13, so you're technically doing this against the rules. Either that, or you are very immature.