There's nothing harmless about The Joker, we all know that.

Batman (Adam West)

4 seconds sound clip from Batman (1966) - The Joker Goes to School (S1E15) TV Series.

You can hear this line at 00:06:09 in the Blu-ray version of the movie.

Quote context

[...]

- The switch, Alfred.

- Good luck, sir.

- Looks sinister, doesn't it?

- Joker released from jail one week ago.... immediately buys control of One-Armed Bandit Novelty Company.

- Makers of coin operated gadgets.

- Gum machines, pin balls, that sort of harmless junk.

- There's nothing harmless about The Joker, we all know that.

- Or about a machine which returns 20 silver dollars for a dime.

- What about the men who install the machine and service it?

- Clean as driven snow and they're even more surprised than we are.

- Ah, it's open and shut. Somebody got to that poor innocent machine and gimmicked it. But why? In the devil's name, why?

[...]