Woo Ping is a level 50 weapon master located in the Trade District at Weller's Arsenal (coords 63, 69) in the human city of Stormwind.
Prior to patch 4.0.1, this NPC taught the skill to wield Crossbows, Daggers, One-handed swords, Two-handed swords, Polearms, and Staves.
See List of Stormwind NPCs.
Named after Woo Ping Yuen, the martial arts choreographer / fight coordinator / action choreographer for numerous Hong Kong cinema films, and more recent movies like The Matrix trilogy and Kill Bill.
Saying his full name quickly sounds like "whooping."
He shares the same facial appearance as Wu Shen, a warrior trainer in Stormwind City.