Well, this was a bit of a surprise.
I'd thought I'd only tested both parents as far as Superposh - and this was last kitten and I'm bored - give up - out, turns out I'd tested the mother against Sassy Swank last week and I got a Sassy Swank kitten back. Which makes the tail recessive to Sassy Swank and a new most recessive.
It's under a special kitten costume but Flair tail is on the Wintercorns costume (thanks to Sandy for pointing that out).
I've now got Flair tail off another cat, and it's on a kitten where you can see the tail.