British author-illustrator Eric Hill, whose iconic puppy character first peeked out from behind the flaps of Where’s Spot? (Putnam) in 1980, died on Friday, June 6, following an illness. He was 86.

Hill was born in London, England, in 1927. By age 16, he had left school and taken a job as a messenger at an art studio, where one of the studio artists encouraged him to try cartooning on his own time. He served in the Royal Air Force from 1945–48, and upon his return, he headed back to the art studio and honed his skills. He created a weekly comic strip and did other magazine sketches as well, and eventually worked in both advertising and graphic design at local firms.

Later, as a freelance graphic designer, simplicity and playfulness remained hallmarks of his art. One of his freelance advertising projects, for which he had created a lift-the-flap device, played a role in Spot’s genesis. In 1978, Hill’s son Christopher, then two years old, was entertained by the flap, and the surprise underneath, on one of his father’s advertisements. Hill found a way to incorporate that type of mechanism into a seek-and-find story about a puppy looking for a ball.

A handmade dummy of the book made the rounds and, via one of Hill’s friends, was taken to the Frankfurt Book Fair, which helped secure him a publisher. Hill’s eye for design carried through the publishing process for his debut, as he carefully chose fonts and insisted on using an ample white background for each of the lift-the-flap scenes. Where’s Spot? quickly became a hit and launched a long line of bestselling sequels, an animated TV show, and numerous merchandising deals. The books, more than 50 titles in all, have sold more than 50 million copies and have been translated into 65 languages.

“I consider myself very fortunate indeed to have created a character which has captured the imagination and enthusiasm of so many children worldwide,” Hill once said in an interview. “They are my family, and Spot belongs to them all.”

In 2008 Hill was honored with an OBE (Order of the British Empire) for services to children’s literature. In recent years, he lived in California with his wife Gillian, and they also spent some of their time in France. He is survived by Gillian, son Christopher, and daughter Jane.