Grinkle is a level 50 quest giver located in the Valley of Strength in the orcish city of Orgrimmar.
He starts the quest: [11] Could I Get a Fishing Flier? (Repeatable) (Stranglethorn Fishing Extravaganza)
NOTE: He is only available before and during the weekly Stranglethorn Fishing Extravaganza.
See List of Orgrimmar NPCs.