Animation : The legalities of an animated series by Colleen McWatters

Hi All, This may not be the right forum to ask this question, but here we go. I am currently working on a stop motion animation web series. After 5 years of hard work, we are finally in production of season 1 which consists of 8 episodes that are 20 minutes each. We plan to release episode 1 this summer. We have obtained copyrights on all 8 scripts for season 1. Now here is my question. Do I need to copyright or trademark my images and puppets also? And if so, how would I go about doing that? For example, The Simpsons is set in Springfield which consists of a large cast of characters, all of which are a part of the Simpsons brand. I have a similar scenario in which I have a town, Center Square, and 79 puppets that will be on screen throughout the 8 episodes of season 1. So, since the scripts have a copyright, are the characters that appear in the scripts covered by said copyright? Or will I need to copyright each puppet? I have never dealt with the legalities of images before, only written word, so I want to make sure that we develop our brand in a way that can't be legally ripped off. I am sorry that I rambled on, I just want to cover my ass. Thank you in advance for any advice you can give!