The name "Hemingway cats" came from our very own American author Ernest Hemingway who was a big polydactyl cat enthusiast...who knew? His home in Key West is now a museum and houses 60 of his polydactyl cats (which are obviously not alive). If you're curious to know more the topic, click this link! There's a long history of where these cats originated from and where their nicknames came from.
I have only seen one other Hemingway kitty at the shelter before, but she was older and pretty grumpy...so I could never grab her paw to take a picture of it. Our current polydactyl or Hemingway kitty from the shelter is appropriately named Mittens. He is a sweet and friendly kitten that is only 4 months old and has an extra toe on his front paws. I circled the double toe in red so it would be easier to spot. His paws are SO cute and it looks like he's wearing Mickey Mouse gloves on or sporting a huge oven mit. And to top if off he has an absolutely adorable personality, just look at the first and third picture...all he wants is some cuddling! :)
Other nicknames for polydactyl cats according to wiki: Boston Thumb cats, boxing cats, conch cats, snowshoe cats, thumb cats, mitten cats, and six-fingered cats.