Forum registration is too hard

[Pete Mack]

Alive without breath,
As cold as death;
Never thirsty, ever drinking,
All in mail never clinking.

The trouble with this:
It could be fish.
It could be fishes.
It could be fissssshhesssssss.
Precious. Preciousss. Gollum.

[rhutson]

Upon reflection, I think that is a very clever "question". I interpreted it as a puzzle rather than a riddle and solved the riddle like a warrior would.

That's the "best" captcha I've come across, and it's certainly the most memorable. Well done!