Note: Sorry for the late start, I've been dealing with some medical issues, so try to bear with me the next couple days.
This is the Pokemon Pickachu tail and buttplug available from Epic Tails. It costs $90, but that does include the headband too, so it really is a great deal if you think about it. Just don't think about it too hard.
Cut off from a wild fainted Pikachu who probably won't be needing it anymore. We bring you this battle trophy! (or butt plug) Make your friends jealous as you transform into a real Pikachu while they stand around in their fake Pikachu pajamas and shirts.
The tail is approximately 21 inches long and 15.5 inches at the widest. It has a sturdy frame to keep its bolt-shape yet it's soft to the touch because of it's fleece fabric and high quality stuffing.
I dunno, I feel like you'd have to have a pretty tight butt to be able to support that whole tail. I'm pretty sure the weight of that thing would just cause it to fall out every time I tried to put it in. "Sounds like you've got a case of the loose caboose." My doctor said the same thing.
Keep going for one more shot of the plug being held up like its in use.