Len Wein was an American comic book writer and editor born on June 12, 1948, in New York City to a Jewish family. He passed away on September 10, 2017. Wein entered the comic book industry in 1968, publishing his first story in DC Comics' Teen Titans issue 18. He subsequently worked for both major American comic book publishers, Marvel and DC, becoming one of the most influential writers and editors of the 1970s. He was inducted into the Will Eisner Comic Book Hall of Fame in 2008.

Wein is most renowned for co-creating some of the most enduring characters in popular culture. For Marvel Comics, he co-created Wolverine, who first appeared in The Incredible Hulk issue 180 in 1974. He also wrote Giant-Size X-Men issue 1 in 1975, introducing a new, internationally diverse team that included characters he co-created such as Storm, Colossus, and Nightcrawler, effectively revitalizing the X-Men franchise. For DC Comics, he co-created the supernatural hero Swamp Thing, as well as characters like the Human Target, Lucius Fox, and Amanda Waller. He also served as the editor on the landmark limited series Watchmen.

Beyond comic books, Wein wrote for numerous animated television series. His credits include scripts for shows such as Batman: The Animated Series, for which he received Emmy recognition, Transformers, Beast Wars: Transformers, Street Fighter, and Ben 10: Alien Force.

Through his work in comics, Wein became an original creator whose characters have been adapted extensively into Japanese anime and manga productions. His role in these works is typically credited as original creator, reflecting the provenance of the characters rather than direct involvement in the Japanese productions. For instance, he is credited as the original creator of Wolverine for the anime series Marvel Disk Wars: The Avengers, which aired in Japan in 2014. Similarly, he is credited as the original creator of Amanda Waller for the anime series Suicide Squad ISEKAI, which premiered in 2024. Other anime and manga projects that credit Wein as an original creator or character originator include the Wolverine anime, the X-Men manga, and the film Batman: Gotham Knight.

Wein's significance to the entertainment industry lies in the foundational work he did in American comics, which provided the source material for countless adaptations worldwide, including in the Japanese animation industry. His creations have become archetypes within the superhero genre, and his 1970s work on the X-Men, in particular, established a model of diversity and global representation that continues to influence media globally. Following his death, both Marvel and DC Comics issued public statements mourning his loss, and actors such as Hugh Jackman, who portrayed Wolverine in film, publicly acknowledged his contribution to the characters they brought to life.