Batman: Arkham Knight - Season of Infamy: Most Wanted Expansion is downloadable content released in December 2015. It adds four new missions to the game, each featuring iconic Batman villains: Ra's al Ghul, Killer Croc, Mad Hatter, and Mr. Freeze. These missions expand the "Most Wanted" side quests, integrating into the main game’s open world. Players confront unique challenges tied to each villain, further exploring their stories and connections to Gotham. The DLC also introduces new areas and gameplay mechanics specific to each mission.