Stan Lee passed away from heart failure.

The comic book legend - who died on November 12 - passed away from  heart failure and breathing problems, according to his death  certificate.

TMZ reports that Stan was also suffering from aspiration pneumonia,  which happens as a result from inhaling food, stomach acid or saliva  into the lungs.

Stan - who was 95 when he passed away - was laid to rest after a  "private closed ceremony" on Friday November 16.

Stan's POW! Entertainment company shared a message on Twitter, which  read: "Stan was always adamant that he did not want a large public  funeral, and as such his family has conducted a private closed  ceremony in accordance with his final wishes. 

"Our thoughts and prayers  continue to be with him. We at Stan Lee's POW! Entertainment are  working on putting together a tribute befitting the greatest creator  of our time and the father of modern pop culture. 

"T he grandeur of Stan  makes this a monumental task, and we hope to have more info in the  days to come. In the meantime, we understand and share your desire to  commune with fellow fans, and we have set up a tribute wall on  therealstanlee.com where we can all share our thoughts, prayers and  messages of support. We look forward to joining all of Stan's fans in  celebrating his extraordinary life and legacy."

Stan began his career as a comic-book writer, editor, film executive  producer, actor, and publisher, in 1935, and has created or co-created  some of the most famous comic book characters - and later on-screen  heroes - that are still loved by millions today. 

In collaboration with  artist Jack Kirby, Stan created the likes of Black Panther, Nick Fury,  the Hulk, the X-Men, the Fantastic Four, the Inhumans, and Scarlet  Witch, as well as teaming up with his own brother Larry Leiber and  Jack on the creation of Ant-Man and Thor, and again with Jack, Larry,  and Don Heck on one of Marvel's most iconic superheroes, Iron Man.

Bang Showbiz