1. Say "reptile" in front of one.
2. Pretend to roast a marshmallow in the dragon's flame.
3. When you get up from the couch, rub your backside and pretend its bruised.
4. If a dragon invites you to lunch, ask if you are the main course.
5. When riding, say "giddyap."
6. Tell the dragon that its most prized treasure is a forgery.
7. Say "we're off to see the lizard" when being taken to meet the rulers.
8. Pretend to look for shed skins or scales
9. Find a bald spot
10. Try to use logic. I guarantee they will correct you before you die.
11. Tell them Einstein was wrong.
12. Poke one in the eye
13. Give one a very spicy pepper or food, then laugh evilly while it eats.
14. Read it a children's book.
15. Say that humans are smarter.
16. Ask if it wants to meet your leader, then introduce it to the village idiot.
17. Sing " Fly Me to the Moon." It will think you really want to do those things
18. Ask to be shown a heavy light, jumbo shrimp, waterproof towel, elbow grease, or other such things.
19. Ask for a souvenir.
20. Find scientific evidence to prove that dragons do not and never will exist.

These are various methods tried over the years to find what dragons really hate. The answer: humans that don't believe. Keep an eye out for insults from Eden.