He will collect full decks of Darkmoon Cards from players.
"Welcome to the Darkmoon Faire adventurer! We have collected wonders from all over the world for your perusal. Oh and please let me know if you manage to collect a set of the lesser Darkmoon cards, as the master... I mean I would be keenly interested in them."
- Patch 4.3.0 (29-Nov-2011): Added to Darkmoon Island; no longer a vendor.
- Patch 1.6.0 (12-Jul-2005): Added.