Minifigures, also known as Collectible Minifigures, is a theme introduced in May 2010. Each series consists of polybags which contain 1 of 16 unique and exclusive minifigures. A new series is released every three to four months, with sixteen new unique and exclusive minifigures in each series (excluding the 8909 Team GB Minifigures, which includes nine minifigures, 71001 Minifigures Series 10, which includes 17, 71017 The LEGO Batman Movie Series, which includes 20, and 71018 Minifigures Series 17 which has 17). The minifigures can be based on movies, sports, fiction, history, or just average "a-day-in-the-life" professions. Each minifigure contains new elements in the form of accessories or uniquely printed body parts. Thirteen regular series, and three special series, have been released