Hildon

Hildon is a zombie who resembles a stitched-up vampire whom Nami, Chopper, and Usopp met in a tree while hiding from the Cerberus. He appears to act as a messenger in-between the members of Thriller Bark's Mysterious Four, reporting to them noteworthy events that are happening throughout island ship before it fell.

Appearance
Hildon has a bat like body with a black cape that are also his wings that enable him flight, and legs capable of suspending him upside down. He has sharp fangs and claws, and his eyes, if not sunken, seem to have strange tattoos encircling them. Above his right eye is the number 21. When he first apeeared, he carried with him, over his back, a very large long-necked bottle of what appeared to be liquor.

History
After the three Straw Hats escaped from the Cerberus, Hildon offered to take Nami, Usopp, and Chopper on a carriage ride to the mansion where Hogback lives.

In the carriage drawn by a Centaur and by what looks like a hound ridden by a hunchback holding a lantern, Hildon takes the three through the forest of Thriller Bark and leaves them in a graveyard. He then flies off towards the mansion.

Later, after the Straw Hats begin their counter attack on Thriller Bark, he warns Moriah of this as well as when Ryuuma is beaten by Zoro.

Moriah, after being beaten by Luffy, used his Shadow Asgard technique to increase his power by absorbing all one thousand shadows in Thriller Bark, thus leaving Hildon a hollow shell once again.

Trivia

 * Hildon bears a striking resemblance to Eyeshield 21's (an American football sports manga also published in weekly shonen jump) Yoichi Hiruma. Hildon also has the number 21 over one of his eyes and when in flight is similar in appearance to the cartoonish bat mascot of the Deimon Devilbats, Hiruma's team. More then likely this was an intentional in-joke by Oda.