Andrew Mendoza from Wharton county, Texas, confessed to police he "messed" with his neighbour's mare after he was stood up by his girlfriend, The Sun reported.
The 29-year-old man, however, said he was only trying to make it pregnant with a "horse-man baby".
"I was at my house waiting for my girlfriend to call. I told myself that if she didn't call me, I was going next door and mess with the neighbour's horse," he said.
"I was trying to make the horse have a baby. I was thinking it would have a horse-man baby," the daily quoted him as saying.
Mendoza pleaded guilty and was sentenced to four months in jail.
