The Colorful Boppy Pillow Decoration is a CAS pose prop that has been turned into an in-game decoration. It comes in two different sizes, the smaller one being the same as the CAS prop size and the larger one slightly bigger. You can download both or choose which one you want. You should be able to find it in the clutter, decoration (both misc and kids), sculpture, and kids furniture section. If you have a lot of CC like me and are struggling to find it, you can just search for a boppy pillow. The CAS override can still be downloaded with this in your game, but remember that you can only have one CAS override. So, choose the one you want to add to your mods folder to ensure it works properly.