“I always visually gravitated toward comics, but I wasn’t somebody who read every story,” he said of his Jersey City childhood, which was much more about finding places to skateboard than see art. “I wasn’t taken to galleries.”

He attended the School of Visual Arts in Manhattan and then started traveling to Japan, further embedding himself in the cartoon aesthetic. In the 1990s the KAWS name became associated with on-the-fly Manhattan street projects.

“I haven’t painted illegally since about 2001,” Mr. Donnelly said. With age came a more conventional life: He’s married to an artist and has two young children.

Given the toys and characters he’s surrounded by at all times, “I had to have kids just to make it not seem weird,” Mr. Donnelly joked.

In a season when he seems to have it all — the fun of childlike pursuits plus serious auction clout and designing stores for Dior — he made no apologies for his low-to-high success. But he did it in his soft-spoken way.

“Honestly to me, it would be weird to be an artist these days and not be working in all these spaces simultaneously,” he said.