Guillermo del Toro, James Gunn Mourn Neal Adams, Comic Book Legend

The entertainment world is in mourning Friday as comic book legend Neal Adams died at the age of 80.

Adams is responsible for creating a number of characters for both DC Comics and Marvel, including Batman foes Man-Bat and Ra's al Ghul, and Green Lantern John Stewart, cited as one of the earliest Black superheroes. For Marvel, he created Mockingbird and was one of the foremost artists on X-Men and The Avengers. He also created Bucky O'Hare, a green hare that made the jump from comics to Saturday morning cartoons in 1991.

Adams was also a fierce advocate for creators' rights in the comic book industry. He attempted to start a comic creators' union in the 1970s. According to True Believer, a biography on Marvel scribe Stan Lee, Adams famously wrote "Do Not Sign This Contract! You Will Be Signing Your Life Away!" across a contract from Marvel that barred freelancers for taking copyright for things they created, following the then-recent creation of the federal "work-for-hire" law. He also helped to stop publishers from destroying original comic art, leading to companies returning the art to the artists, letting them keep it or sell it.

For both his huge influence on popular culture and his efforts fighting for creators' rights, people across the worlds of comics and film their memories of the legend.

James Gunn, director of Guardians of the Galaxy and The Suicide Squad, shared an image of one of Adams' classic Batman covers.

"RIP to Neal Adams, one of the greats," he wrote.

Guillermo del Toro, who directed Nightmare Alley and The Shape of Water, highlighted Adams' work designing movie posters.

"R.I.P. Neal Adams- one of the first and great stylists to push USA comics to a new level. One of his lesser-know works was pencilling the excellent PHANTOM OF THE PARADISE poster for Richard Corben to color," he wrote.

Award-winning editorial cartoonist Ruben Bolling of Tom the Dancing Bug fame, shared pages from Adams' run on Batman featuring Ra's al Ghul and his daughter Talia, whom Adams also created.

"RIP to Neal Adams, one of the most exceptional, innovative, and influential comic book artists ever. This sequence really got to me when I was nine years old," he wrote.

Writer Neil Gaiman also celebrated Adams' work with a Batman page.

"Neal Adams is gone. He was the reason I drew Batman in every school exercise book. He reinvented the look of comics pages and characters, made me care about comics at the point where I didn't care any more, and I wish I'd been lucky enough to write a story he drew. #RIPNealAdams" he wrote.

"RIP Neal Adams. I only met him a few times, but he was always great to talk to. His art alone would have changed comics, but his crusading for creators' rights did too. An amazing artist and an admirable guy. He'll be much-missed," Kurt Busiek, writer of Astro City and Batman: Creature of the Night, wrote. "First piece of comics art I ever bought was a Cyclops sketch by Neal Adams, at the first con I ever attended."

Comics writer Jimmy Palmiotti shared both a splash page Adams drew along with a heartwarming memory.

"The Amazing Neal Adams splash page. Just look at this beauty. Not a lazy bone in his body. A master. Rest in Peace. He came up to m at a show and said to stop by his booth, which i did and he was proud to show me this splash in Black and White. I gushed for about a half hour at every detail. He just smiled," Palmiotti wrote.

"one thing that really sticks out to me re: Neal Adams was, when I was researching my Paul Smith piece for [comics news site ComicsXF], research paths led me to his work as well, and in every single interview he was so great about speaking up for and giving credit to the people he worked with," Eisner-winning comics journalist Nola Rose wrote. "It's not shocking, given he was known for championing creators' rights, but it's still just heartwarming as hell whenever it comes up in an old interview."

Adams' former publishers also mourned his loss.

"Marvel is saddened to learn artist Neal Adams has passed away. Neal's photorealistic style helped shape the Marvel Universe and beyond, inspiring generations of comic artists as he championed their mentorship & growth. Our thoughts are with his family and loved ones at this time," Marvel Entertainment said.

"The modern comic landscape would not be what it is today without the incomparable work of Neal Adams. Neal portrayed heroes as both super and human in equal measure. His work on Batman, Green Lantern, and many more was revolutionary. DC joins the world in mourning his loss," DC Comics wrote.

"We are saddened to learn of the loss of legendary artist and Heavy Metal alumni Neal Adams who championed the rights of creators and influenced generations of artists, giving many a boost or break into the industry," Heavy Metal magazine wrote. "Here's his story and cover from July 1979."

Adams is survived by his wife, three sons, two daughters, six grandchildren and one great-grandson, according to The Hollywood Reporter.