Samurai Jack2001

Jack:
[Is only allowed one question to decide which of the two worms is the "magic" worm, armed only with the knowledge that one tells the truth and the other lies] If you were your brother, which one would you say was the magic worm?

Worm #2:
Which one are you asking?

Jack:
It doesn't matter.

Worm #2:
Hmmm. That's easy. It's him!

Worm #1:
Of course! It's me!

Jack:
Then I choose *you*.

[chooses Worm #2 instead]

Worm #1:
He knows!

Worm #2:
What makes you choose me? I told you it was him!

Worm #1:
Yes, me!

Jack:
If you were the truth-telling one then what you said would be a lie because you will answer truthfully what your lying brother will say. Therefore I can safely say that the answer will be the opposite of what you say. On the other hand if you were the lying worm then you will tell me what your truth-telling brother will say but it would be a lie, therefore the answer will also be the opposite of what you say. Understand?