Now, I've always HATED Skulduggery's rashness and recklessness, but I've managed to think up some ways to deeply annoy that walking fish-bone (Sorry Skulduggery, but it's true).
1. Take his hat hostage. It may not seem annoying, but trust me, IT IS.
2. Deliberately dent his car.
3. Act like Clarabelle whenever you're around him.
4. Step on his hat.
5. Whenever he says a joke, give him the 'dude, what the hell is wrong with you' look.
6. Call him a walking fish-bone.
7. Insult his dead family (No hard feelings, Skulduggery).
8. Sit in his car with muddy shoes/clothes.
9. Change his finely tuned radio.
10. 'Borrow' his .38 Smith and Wesson Revolver.
11. Get mud on his exquisite suits.
12. Get him to visit me.
13. Make him wait for you. In the rain.
14. Insult his hat.
15. Insult his exquisite suits. (No Ghastly, your tailoring is AMAZING. You should really consider making me a labcoat).
16. Play pop music whenever he's around you.
17. Give him a lecture explaining how the sparrow does NOT fly South for Winter (even though it does, Skulduggery HATES having his punchline [literally] questioned).
18. Brush his teeth when he's 'asleep' and leave the toothpaste smeared all over his skull.
19. Draw all over his face with permanent marker when he's 'asleep'.
20. Invite him to a party where he will meet (and argue with) Captain Jack Sparrow, Tony Stark, Sherlock Holmes and The Doctor.
Do you think those ways are decent enough? Comment what you think will annoy him!