The next test is... the blue... blue whistle? That's a weird name. Anyway, he wants you to catch a Monster by that name. It won't take long since the Monster is said to be at the Yak Farm. God speed~
After accepting the quest, take the road north out of town. When the road forks, head west and when it forks a second time, head north again until you reach the Yak Farm. Blue Whistle can be found in the Yak Farm and the surrounding area. Kill one and then return to Guild Official Oveli.
Wow, was that Monster that strong? Your clothes are a mess. There are 3 tests left now. I think you'll be able to finish them faster that I thought.