An icon of the ’60s is taking on an icon of the Internet age.

Robert Crumb, the counterculture illustrator known for characters such as Mr. Natural and Fritz the Cat, has filed a copyright infringement lawsuit against Amazon.com Inc., accusing the Internet retailer of using his images without permission.

Jules Zalon, Crumb’s lawyer, said people who searched the Amazon Web site for a product that it didn’t carry were shown Crumb’s famous “Keep on Truckin’ ” image – a big-footed man in full stride, leaning sharply backward – with instructions to keep on looking.

The lawsuit seeks unspecified damages. It came after the two parties were unable to agree on how much Amazon should pay for using the image, which over the years has been memorialized, among other places, on the mud flaps of trucks.

Amazon has not filed a response, and a spokeswoman declined to comment.