In Final Fantasy 7 (VII) Yuffie INTERmission DLC you must find all Happy Turtle Flyers for The Happy Turtle Ad Campaign Side Quest.
Finding all Turtle Flyers also unlocks the Turtle-tastic trophy. There are 6 Happy Turtle Flyers in total. When you get close to them you will hear a Happy Turtle Jingle music playing. Each of them has such a Jingle. It can be hard from far away.
Quest Start – The Happy Turtle Ad Campaign
The first step is to talk to Old Snapper, which is an automatic main story objective during Chapter 1. The objective is called “The Happy Envoy” on the map, marked as a blue main objective.
He will tell you about 6 Happy Turtle Flyers scattered across the area. Now they spawn and can be interacted with. He also gives you a list of hints.
Happy Turtle Flyer Locations
Happy Turtle Flyer #1
Found in the south-central part of the Residential Area, on a playground where some children are. You must run through some stacked cardboard boxes to find the flyer behind.
Happy Turtle Flyer #2
In the southeast part of the Residential Area, there’s a flying Turtle Balloon. Climb over the box to the right of it, then throw your weapon to destroy it. Climb back over the box and the flyer will have dropped on the ground.
Happy Turtle Flyer #3
At the motel in the northwest of the Residential Area. There’s a guard dog on the balcony. You must hide behind the boxes and move forward when he sleeps. On the left wall in front of the dog is the flyer on the wall. Only move up one box at a time when he goes to sleep. Then after the third box wait until he sleeps again and quickly grab the flyer. His owner will come after you grab the flyer and the dog will then leave you alone.
Happy Turtle Flyer #4
In the north-central part of Residential Area. When you go there, a cat will run away, dragging the flyer with it. Yuffie will make a comment about it. Follow the cat and check at the very end of the area (northern edge) to find the correct cat behind some oil barrels.
Happy Turtle Flyer #5
On the path to the train station, east of the Residential Area (Pillar Plaza), there’s a Happy Turtle Flyer on a board. This one is very easy to reach.
Happy Turtle Flyer #6
The last Turtle Flyer is in the Abandoned Talagger Factory area. You can enter via Pillar Plaza, where you picked up the 5th flyer. Enter the fenced area where a guard is standing and reach the northeast area of the Factory. There are 2 scorpion-looking enemies, defeat them, then destroy the crates on the left. The flyer is behind those crates, by far the best hidden one of all. See the 2nd screenshot showing the crates and the 3rd for what it looks like after the crates are destroyed.
That’s all of the Happy Turtle Flyers in FF VII Remake. After finding the last one, you should automatically get a prompt to return to the quest giver. Choose yes to save some time (you can also walk back to him manually later). Talk to Old Snapper, he will be pleased that you found his six flyers and you’ll earn the Turtle-tastic trophy.