Herodotus was an early kind of historian, in the context in which he was relating his histories he was as much an entertainer as much as a historian so he repeated every fun and weird story he heard. He did qualify the dog-headed men specifically as a thing he had heard in a ironic Greek tone, he was relating an entertaining tale, not trying to persuade you that dog-headed men really exist.

A human body with a canine head. My guy Herodotus wasn’t telling tall tales at all, he was merely giving accounts of some of the very first furry conventions. These “dog-headed” men were wearing fursuits!