Here it is:
https://www.youtube.com/watch?v=IX2EfnTc_Eg
Context:
Celestial dragons are basically this aristocratic ruling class that no one is allowed to harm. Doing so will literally call down an entire navy fleet to destroy the island if you dare. They're all pieces of shit, and main character Luffy here just had to watch one of them harm his pal to decide to clobber him.
CE's Resident Scotsman.
http://i.imgur.com/ILz2ZbV.jpg