Mike Oswald with Multnomah County Animal Control said the goat was "taken into custody by transit police for lack of proper fare" after it was spotted on the bus.
Someone actually called 911 to report the sneaky passenger on bus route number 14. Police got a good chuckle and spread the word that "an unauthorized kidd" was riding the bus alone.
The 35 pound goat was eventually captured without incident and taken to Multnomah County Animal Services in Troutdale, Oregon.
Employees were trying to find its owner, including through searches on Craigslist.
They said the female Pygmy goat had a black collar with a yellow tag on it, but the tag was so worn, it was impossible to read.
But as it turned out, it was the goat's brief moment of fame that brought out her owner. The goat's family saw the story on TV and quickly called Animal Control to claim her.
The goat's name is Poppy and she was a recent gift to a southeast Portland resident who said it was unclear how the goat got out of a gate.
Poppy seemed to take the whole day in stride, chomping on hay and grain at the shelter before she was reunited with her owner.