It has been five years since Rocksteady releasedBatman: Arkham Knight, and the studio is still “releasing” new Batman skins for the game. A free update adds two new skins, the “Anime Batman Skin” and the “Zur-En-Arrh Skin,” to the Caped Crusader’s wardrobe of costumes.

Both of the skins were technically already available inArkham Knight, but were only accessible to players who logged onto the game’s official forums using a linked WB Games ID. Now, the costumes are available to everyone who owns a copy ofArkham Knight. As with all of Batman skins included in theArkhamtrilogy, each of the costumes has a special backstory inBatman’s long history.

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The origins of the Zur-En-Arrh skin can be traced back to 1958. The suit first appeared in Batman #113, when the Caped Crusader travels to a planet called Zur-En-Arrh and meets its version of Batman, who wears the Zur-En-Arrh costume. The pair join forces to fight an unnamed alien race and an army of giant robots. During the adventure,Batman gains Superman-like powersfrom the planet’s sun and it concludes by hinting that the entire journey may have just been one of Batman’s dreams.

Batman’s adventures on Zur-En-Arrh were referenced again during the 2006Batman R.I.P.story arc by Grant Morrison. In that comic, it is revealed that Batman’s Zur-En-Arhh alien counterpart is really a backup personality that Bruce Wayne invented for himself in the event that his real personality was ever mentally compromised. The alter-ego is a more violent and unhinged version of Batman’s regular persona.

The Anime Batman skin is based on the 2008 anthology filmBatman: Gotham Knight, which is composed of six segments produced by different Japanese animation studios. The stories are a loose continuation of Christopher Nolan’sBatman Beginsand is visually based on the Japanese anime art style. The skin included inArkham Knightcomes from the “Field Test” chapter, which was written by Jordan Goldberg and animated by Bee Train.

For fans who still haven’t played it,Batman: Arkham Knightwas recently made available on GOG for PC. Earlier this year, it was also revealed that the title would be backward compatible on the Xbox Series X/S and the PS5. Despite releasing five years ago, this is not the only time in 2020 that Rocksteady has added more skins toArkham Knight. In January, the developer added an Earth-2 Batman skin to the game.

Batman: Arkham Knightis available on PC, PS4, and Xbox One.