Longtime friend and caretaker Lynn Caponera said she was with him when Sendak died at a hospital in Danbury, Conn. She said he had a stroke on Friday.
"Where the Wild Things Are" earned Sendak a prestigious Caldecott Medal for the best children's book of 1964 and became a hit movie in 2009. President Bill Clinton awarded Sendak a National Medal of the Arts in 1996 for his vast portfolio of work.
Sendak didn't limit his career to a safe and successful formula of conventional children's books, though it was the pictures he did for wholesome works such as Ruth Krauss' "A Hole Is To Dig" and Else Holmelund Minarik's "Little Bear" that launched his career.
"Where the Wild Things Are," about a boy named Max who goes on a journey — sometimes a rampage — through his own imagination after he is sent to bed without supper, was quite controversial when it was published, and his quirky and borderline scary illustrations for E.T.A. Hoffmann's "Nutcracker" did not have the sugar coating featured in other versions.
Sendak also created costumes for ballets and staged operas, including the Czech opera "Brundibar," which he also put on paper with collaborator Pulitzer-winning playwright Tony Kushner in 2003.
He designed the Pacific Northwest Ballet's "Nutcracker" production that later became a movie shown on television, and he served as producer of various animated TV series based on his illustrations, including "Seven Little Monsters," "George and Martha" and "Little Bear."
But despite his varied resume, Sendak accepted — and embraced — the label "kiddie-book author."
"I write books as an old man, but in this country you have to be categorized, and I guess a little boy swimming in the nude in a bowl of milk (as in 'In the Night Kitchen') can't be called an adult book," he told The Associated Press in 2003.
"So I write books that seem more suitable for children, and that's OK with me. They are a better audience and tougher critics. Kids tell you what they think, not what they think they should think."
During that 2003 interview, Sendak alsoshe felt as if he were part of a dying breed of illustrators who approached their work as craftsmen. "I feel like a dinosaur. There are a few of us left. (We) worked so hard in the '50s and '60s but some have died and computers pushed others out."
Sendak, who did his work in a studio at the Ridgefield, Conn., home he moved into in the early 1960s, never embraced high-tech toys. He did, however, have a collection of Mickey Mouse and other Walt Disney toys displayed throughout the house.
