I have a friend who owns a goldfish farm about one year ago. Amongst his last few batches of goldfish was this crescent tail telescope eye which he gave to me about a year ago. I learnt that crescent tail telescope eye are almost extinct now as the preference is for butterfly and veil tail or broad tail.
This tail form can be seen in some traditional Chinese paintings of telescipe eye where the tail tips are pointed at the end.


And this was how she looks like 6 months ago.

And this is how she looks like one year ago whn I first got her. Picture was taken at my friend's farm.