Necrotech_Master wrote: »as far as i am aware, there are no collectible/outfit options to change the style of tails that are unique one offs, most of them can be modified a little through the use of skins or certain polymorphs
skins can change the "look" of the tail but its usually just a different color pattern, not changing the tail entirely like that
certain polymorphs (such as the cadaverous assassin) give you a skeletal tail which is by far the "largest" change to look besides the skins
i also am not sure if the tail is something you can really modify too much on the character during creation either (i only have 1 khajiit and went through creator fast so didnt pay attention, and its been like 6 years since i created my argonian)
It's the Sporty Tail Tuft.
Sadly it was datamined with the Morrowind PTS back in 2017 and never released to players.
Even had a description:
"You'll swing your tail to the Two Moons Dance with pride when it's tipped with the so-sleek Sporty Tail Tuft. Clan-Mother approved!"