It was a random shiny I found while hatching rockruffs... I blundered into the grass and ran smack into a shiny mudbray. This was after I'd already hatched and evolved one. I was holding it for trading, and I decided to use it this time ^_^ You're welcome!
Yes, I still need the vulpix. I've asked in the shiny thread for one but no one has responded. And the "I guess not" is from "It's been over a week with no response so I guess it's not happening after all"