A woman in her sixties was walking her terrier at Moreton-in-Marsh, Gloucestershire, around 7pm on October 28, when she met up with the flasher.
The dog, not impressed, growled and bit him on his upper right arm.
"This was clearly an upsetting incident for the woman and her dog,” said Sergeant Ian Dowling, of North Cotswolds police, said in a press release
. “The animal seems to have acted instinctively and was not urged to attack the offender.”
The man is described as being slim, around five feet two inches tall, and having “bluey-brown” eyes. He was wearing navy blue tracksuit trousers, a light blue top and a black hat.
"We're looking for any information or description that might help us with the investigation,” said Sergeant Dowling.
"Naturally because of the nature of the incident, we are keen to hear about anyone seen with a dog bite on his right arm in the last 24 hours."