Prolific children's book author and artist Eric Carle has died.
His son confirms his father died Sunday of kidney failure at his summer studio in Northampton, Massachusetts.
He was 91.
Carle's most famous book -- ``The Very Hungry Caterpillar'' started out as a bookworm.
He first called it ``A Week with Willi the Worm,'' but he changed it to a caterpillar on the advice of his publisher.
Since it came out in 1969, it has sold more than 40 million copies and has been translated into 60 languages.
Eric Carle was actually born in Syracuse, New York, but grew up in Nazi Germany.
Carle says when he was 13, a teacher secretly introduced him to expressionist art, which was banned at the time. It changed his life.
He said using bright colours, he hoped books like ``Brown Bear Brown Bear What Do You See'' and ``Do you Want To Be My Friend'' would help children overcome fear, and replace it with a positive message.
From the Eric Carle Team: It is with heavy hearts that we share that Eric Carle, author & illustrator of The Very Hungry Caterpillar and many other beloved classics, passed away on 23rd at the age of 91.
— eric carle (@ericcarle) May 26, 2021
Thank you for sharing your talent with generations of young readers. pic.twitter.com/wuMe4eqVXo