There are predictions that this will be the hottest costume for 2017. If you want to become Pennywise for Halloween 2017 then your first decision is what version of It you want to go as. There is the 2017 version and the 1990 version. The 1990 version is a lot more colorful and will be the one most people remember from their childhood nightmare but the 2017 version is more dark and drab with a more modern twist.