Batman’s rogues gallery is one of the most extensive for any comic book character ever, and one of the more complex members of that lineup celebrates his 65th anniversary this month: Mr. Freeze. The character first appeared in Batman #121 (February 1959), where he was known as “Mr. Zero” – he wouldn’t take on the moniker of Mr. Freeze for almost a decade after that.

Mr. Freeze was the creation of Dave Wood, Sheldon Moldoff, and Bob Kane. His original comic book appearance, as Mr. Zero, was originally treated as somewhat of a joke. Armed with a freezing gun, Mr. Zero took on the dynamic duo in some wacky fights that didn’t get much in the way of a marquee treatment. It wouldn’t be until the popular 1960s Batman television series starring Adam West and Burt Ward that the character was treated as a serious threat to Batman and Robin; the show is also what renamed the character to Mr. Freeze, which carried over into the comic books and has stuck ever since.

In the show, the character appeared over the course of three different two-part episodes – each instance portrayed by a different actor. George Sanders originated the role, and was followed by Otto Preminger and Eli Wallach; each took on a slightly different appearance, with Sanders wearing a full cryo-suit and Preminger and Wallach both sporting “freeze collars” instead. Going along with the overall tone of the television series, the character was portrayed quite campy, and eventually being defeated by Batman in every case. Notably, the Batman series gave Mr. Freeze his first alter-ego alias, that of Dr. Art Schivel. In the show’s canon, Batman was responsible for Mr. Freeze’s creation, as he had spilled cryogenic chemicals on Schivel during an attempted arrest.

Mr. Freeze wouldn’t get a true, detailed backstory until the 1992 episode of Batman: The Animated Series, “Heart of Ice.” Written by Paul Dini and directed by Bruce Timm, this marked the first appearance of Mr. Freeze in the series at large, but also featured a complete overhaul of the character. In the episode, Mr. Freeze is responsible for a series of heists being pulled off at GothCorp offices around the city. During his investigation into the heists and the man behind them, Batman discovers that Mr. Freeze is in reality a GothCorp cryogenics scientists, Victor Fries. Victor had been looking for a cure for his wife’s terminal illness, and in order to prolong her life, placed her in a cryogenic sleep. The CEO of GothCorp, Ferris Boyle, eventually shuts down Fries’ work, which sentences Nora to death; Boyle also kicks Fries into a vat of chemicals after a struggle. While Fries survives this incident, he is no longer able to live outside of a sub-zero temperature, and turns into Mr. Freeze accordingly. While Batman must battle against Mr. Freeze in order to prevent him from killing anyone else, he also opts to take down Boyle for his callous treatment of Victor and Nora. “Heart of Ice” has since been regarded as one of the best episodes of the entire Batman animated franchise, and this version of Mr. Freeze’s backstory was eventually retconned into the comic books as well.

Freeze was revamped for the Modern Age in the 1990s, with DC taking a similar approach to how The Animated Series reworked the character: Fries is working on a freeze ray in order to suspend his wife, Nora, in cryogenic stasis so that a cure for her terminal illness can be discovered in the meantime. But Ferris Boyle, GothCorp CEO, learns about the ray, and ops to tell the mob about it. Boyle goes so far as to tamper with the ray itself, resulting in an explosion that kills Nora and lowers Fries’ body temperature to the point where he needs a subzero suit to survive. (Previously, in the comics, Freeze had simply been a mad scientist who injured himself while working on a freezing gun, without any mention of his wife.)

In terms of his powers, Mr. Freeze gleans most of his from the cryogenic suit that he wears in order to keep himself sustained at subzero temperatures in order to stay alive. The suit grants him superhuman strength, and he typically arms himself with a handheld freeze gun in order to slow down or otherwise defeat his enemies.

Unlike many other members of Batman’s rogues gallery, Mr. Freeze rarely ever works with other villains, preferring to work on his own. However, he has forged alliances with the likes of Penguin or Hush, in partnerships that usually involve Freeze creating some sort of cryogenic device for the other party. At one point he traded a subzero device to Nyssa al Ghul in exchange for the use of her Lazarus Pit, intending to use it to bring Nora back to life. However, he doesn’t use the Pit correctly, and Nora is brought back to life as a twisted shell of her former shelf, known as Lazara; she blames Freeze for her condition and refuses to have anything to do with him.

Mr. Freeze has appeared in numerous other iterations of Batman media over the years, from Saturday morning cartoons to video games and just about everything in between. Most portrayals of the character stick to the backstory and power set that was established in The Animated Series, though some break from the mold – for example, the character as he appears in The Batman cartoon series is simply a bank robber, rather than a scientist, who dons a cryo suit and fires icy blasts out of his hands (rather than using a gun). In Batman: The Brave and the Bold, the name of Mr. Zero is restored, as is the character’s original Golden Age appearance, for a brief period of time.

Outside of the 1960s television series, the most notable live-action portrayal of the character has come courtesy of Arnold Schwarzenegger in 1997’s Batman & Robin. The character’s storyline closely follows that from The Animated Series, with Freeze being focused on his wife’s survival above all else. Poison Ivy cuts Nora’s life support, and convinces Freeze that it was Batman who pulled the plug, leading Freeze to ice over the entire city of Gotham. Eventually Batman is able to convince Freeze of the truth, and the two are able to forge a terse alliance before Freeze heads into detainment at Arkham – where he’s able to exact some revenge on Poison Ivy.

After 65 years, Mr. Freeze has emerged as one of Batman’s most complex and interesting foes. A victim of some unfortunate circumstances, his love for Nora drove him to do some unthinkable acts – but he remains perhaps one of the most sympathetic antagonists in comic book history.