The LEGO Batman Movie theme which was introduced in 2017 was based on The LEGO Batman Movie, a spin off of the The LEGO Movie featuring the Batman character. Sets in the theme were released in 2 waves.
2017 LEGO Sets
2017 was a big year for the LEGO movies with the release of The LEGO Batman Movie and The LEGO Ninjago Movie. With these films LEGO gave us a number of new sets and themes around these movies, with many of them already being significant investments for collectors. We also saw a number of new themes released that year including BrickHeadz, DC Super Hero Girls, Boost and of course sets for The LEGO Batman and The LEGO Ninjago movies. However, sadly as it is LEGo did retire the much beloved BIONICLE and Mixels themes as well as the short-lived The Angry Birds Movie theme.