1. By definition, my unicorn is the most perfect unicorn that can be conceived of.
2. But if my unicorn did not exist in reality, we could imagine a unicorn that had all the other properties of my unicorn but that also existed in reality, and this unicorn would be greater than my unicorn.
3. Since by definition my unicorn is the most perfect unicorn that can be conceived of, this is impossible.
4. Therefore, my unicorn must exist in reality.
Good parody, although unless you discount language the concept of perfect still remains.