I sat there for hours fighting and fighting and I never got it.

It's hard but possible. In the room where you find the red fang in the lunar subterrane use a siren. You'll automatically start a fight with some flan princess. Kill them and repeat until you get it

i got 2 or 3 pink tails from them.

I fought almost thirty Pink Puff battles and never gotten a Pink Tail. The only thing they have dropped is an Ether2.

I want to stop playing this game and I can't until I get the Pink Tail!

I have walked into the room twice and the first battle was with a Pinkpuff :S strange. But no tail.
I think I got a megalixir or something on them, oh and a lot of gold.

I thought I was going to march right in there and start fighting until I got a Pink Tail.. however, I only had a few alerts, and the pain of it is that you can no longer find enemies to get them from at that point in the game.. so, I've gone back to an earlier save, and so far have stolen several hundred alerts from the Searchers in the Giant of Babil.. now I just have to get back to where I was before and I'm all set. BUT, in the meantime I am first going to make damn sure that I am not missing anything else important

I've read somewere in a guide that on the gab version its a 1/191 and 1/2 you'll get the rats tail, and on the ps1, Snes versions its 1/255, I know i've read this somewere, and its been confirmed.

Yeah I was never able to get it.