World of Warcraft Quests involving Umi Rumplesnicker:
Winterspring Alliance & Horde
Are We There, Yeti? - (Step 3) Take Umi's Mechanical Yeti and scare her friends with it:
Legacki in Everlook (Winterspring)
Sprinkle in Gadgetzan (Tanaris)
Quixxil in Marshal's Refuge (Un'Goro Crater)
When you are done, bring the Mechanical Yeti back to Umi.
Alliance & Horde
Are We There, Yeti? - (Step 2) Collect 2 Pristine Yeti Horns for Umi Rumplesnicker in Everlook.