I was driving so I couldn’t take a closer look, but today I saw what looked like a small Corgi from behind. When I saw the dog’s head, it looked more like a Chihuahua.

Is there an established breed like this, or is this dog “one of a kind?”

As far as I know, there is no established breed that is a corgi/chihuahuah mix. That doesn't mean that someone didn't breed these 2 dogs together or that there wasn't an "oops".

[MoJosMomma]

I am the proud owner of a rescued Chigi pup, her name is MoJo (Molly Joanna) and she is one of the best pets I have ever had so far. Apparently the breed is fairly new, though, because I am having difficulty finding any information on the breed itself, other than its a mix between Welsh Corgi and Chihuahua.

But to answer your question, yes they exist and they are too cute for words ^_^

MoJosMomma