What are the NPC fetch quests in Pokemon Sun / Moon?

Solution 1:

I haven't beaten the game yet, but here's the list of ones I have encountered so far.

Melemele Island:

• Route 2 Pokemon Center - girl with hat - Cutiefly
• Route 3 - male sightseer - Rockruff
• Hau’oli City Tourist Bureau - scientist - register 10 Pokemon species in your Pokedex
• Hau’oli City Pokemon Center - blonde woman - Drifloon

Akala Island:

• Heahea City clothing store - man - Pyukumuku
• Route 5 Pokemon Center - scientist - Feebas
• Route 8 Aether Foundation trailer - Aether employee - Stufful
• Konikoni City Pokemon Center - Aether employee - Oranguru/Passimian

Ula’ula Island:

• Malie City clothing store - collector - Togedemaru
• Malie City Library - Samson Oak - Alolan Persian (must have the Persian in your party for this quest)
• Route 16 Pokemon Center - Aether employee - Mimikyu

Poni Island:

• Seafolk Village - woman in Steelix boat - Alolan Raichu

Solution 2:

There is missing one in Akala Island in which you could do many times: you need to make 6 Pyukumuku leave Hano beach. You do not battle them, tho.