Roger Slifer, Co-Creator of Lobo and Producer on Yu-Gi-Oh, Has Passed Away

Comic book and animation veteran Roger Slifer, best known for co-creating the character of Lobo, has died, according to a statement released on Facebook by his family.

He was 60 years old. Slifer has been under round-the-clock care since 2012, when he was struck by a hit-and-run driver.

"It is especially sad because in the last month he was making great progress," his sister Connie Carlton posted on Facebook. "He was writing words on his new whiteboard that I bought with money his friend Larry Spears sent for Christmas. He was nodding yes and no to questions. A couple weeks ago they put a passey muir device (speaking valve) in his trach and he said 'yes, no, and hi.' They were getting ready to start him on speech therapy and occupational therapy. Things were finally looking up for him. But God needed another angel."

Carlton said that Slifer had been struggling to breathe at around 9 a.m. and that he passed away in an ambulance between his nursing home and the emergency room.

Besides his comics work for Marvel and DC -- most notably his run on Omega Men with Keith Giffen -- Slifer worked in animation. He worked for Sunbow Entertainment on properties like Jem and the Holograms and G.I. Joe Extreme, and for 4Kids as a producer on the first season of Yu-Gi-Oh.