He has a magic sword that can, in one stroke, chop off either one head, two heads, one tail, or two tails.

This dragon is of a type related to the hydra; if one head is chopped off, a new head grows. In place of one tail, two new tails grow; in place of two tails, one new head grows; if two heads are chopped off, nothing grows.

What is the smallest number of strokes required to chop off all the dragon's heads and tails, thus killing it?

nate, how clever you are!

You really told that Larry kid about his awful typing skills!  I bet he'll think twice about proofreading next time before he says anything!

By the way, since you're such a Grammar Prince, I thought I would help you out on your post:

"Larry, do you happen to be your local PETA [Paranoid English Teachers Anonymous?] representative? Number one, dragons don't exist, so killing one in the "real" world won't happen. Number two, 9 isn't the right answer, it's 6 (I think) so the prince won't be alive to accept jail time.  Number 3, maybe you should get with Bill Nye (that one annoying boy scout dude who thinks everything is scientific, and who voices his "facts" whether they are right or wrong) and talk about "science".  I'm Sorry if this seems disrespectful, because I don't know you, but why can't you eat?  Are you dead?"

I hope Larry learns his lesson!