Details: Should you return to the Abandoned Thrifty MegaMart at night after completing your Ula'ula Island Grand Trial, you will once again be followed by Mimikyu. As you progress through the area, Mimikyu will eventually appear and you will be asked to pet either Pikachu or itself. If you pick Mimikyu over Pikachu, you will receive Mimikium Z. You will also be able to pet it on Route 14 from there on out.