Warriv is an NPC caravan master. He is found in Act One, where he gossips and eventually offers to convey the heroes to Act Two, once Andariel has been defeated.
Warriv is the only NPC with a change of clothing. He wears heavy blue-themed clothes in the Rogue Encampment, and changes into beige desert gear when he arrives in Lut Gholein.
Warriv does not give any quests or quest rewards, and isn't much on quest information or gossip either, for that matter.