One of my favorite episodes from his life is from his high school years. A kid he didn't know very well invited him over to his house. The mom asked him if he wanted a hambuger. He said, "Sure." When the burger was ready, the mom and her son sat down at the table and watch Denny eat the burger. They didn't eat; they just watched Denny. They had gleams in their eyes. When Denny was finished, they asked him if he liked it. He said it was OK, but a little spicy. Then the mom and soon broke out in laughter. "It was DOG FOOD!" they howled.
Denny had 20 issues of his comic, Real Stuff, published, mostly by Fantagraphics. This anthology, also titled Real Stuff, is published by a company in Los Angeles that I've never heard of, called Swifty Morales Press. They did a great job -- the book is a beaut. Link