Well, you're going the wrong way.
3 seconds sound clip from the The Last Unicorn movie soundboard.
You can hear this line at 00:42:08.910 in the Blu-ray version of the movie.
Quote context
[...]
- Be wary of making a magician angry! If I chose I could turn you into a frog...!
- I should laugh myself sick. Have sense, man.
- What were you going to do with the last unicorn in the world? Keep her in a cage?
- Oh, you don't even know where we're going!
- Do you think it matters to me?
- We are journeying to King Haggard's country to find the Red Bull!
- Well, you're going the wrong way.
- I'm sorry, but you were going the wrong way, magician.
- Haggard's fortress. We'll be there tomorrow if we walk all night.
- Where does King Haggard keep the Red Bull?
[...]