Just as she'd put a false horn on a real unicorn to make them see the unicorn.
6 seconds sound clip from the The Last Unicorn movie soundboard.
You can hear this line at 00:19:19.677 in the Blu-ray version of the movie.
Quote context
[...]
- And she has them believing that poor old ape with a twisted foot is a satyr!
- Illusions! Deceptions! Mirages!
- Your Mommy Fortuna cannot truly change things!
- That's true, she can only disguise. And only for those eager to believe whatever comes easiest.
- The Midgard Serpent. It's got the whole world in its coils.
- Just as she'd put a false horn on a real unicorn to make them see the unicorn.
- I know you. If I were blind I would know who you are.
- I am called Schmendrick, the magician. You wouldn't have heard of me.
- I entertain the sightseers as they gather for the show.
[...]