When you first step into the Dremuchij area in Metal Gear Solid Delta, the living, breathing forest contains a good number of collectibles inside. Here, you will also find three Kerotan and Ga-Ko, all hidden in the area. All these count towards trophy achievements and a 100% collectibles number, so it makes sense to go after them right from the earliest areas in the game.
Location of All Kerotan and Ga-Ko collectibles in Dremuchij
You must search Dremuchij South, Dremuchij North, and the Dremuchij Swampland to find all three Kerotan and Ga-Ko collectibles.
Kerotan #1 and Ga-Ko #1| Dremuchij South
In the starting area, after you get your backpack, lie prone under the tree and then take the route left. Follow the grass-covered narrow route, and you will find Kerotan and the Ga-Ko in this area on your left on the rocks.
Ga-Ko #2| Dremuchij Swampland
Get to the swamp area, and get on the small piece of land in the middle of the swamp. You will find the Ga-Ko at the bottom of the trees, right next to the bee nest. This Ga-Ko collectible is a bit difficult to notice, as the surrounding plants do a good job covering the item.
Kerotan #2| Dremuchij Swampland
From the spot we picked up the Ga-Ko #2, take the route north. After a short walk, you will find the Kerotan to your right next to the tree.
Ga-Ko #3| Dremuchij North

Pass the second guard, behind the tree with the bee nest. You’ll find an unusual silver-colored rock, the Ga-Ko, blending into it. Take out the silencer and shoot at it to unlock the third one.
Kerotan #3| Dremuchij North

Head to the fourth guard in Dremuchij North, follow the tree log on the ground, and at the end, you will find the Kerotan right on top of the broken tree stump.
Metal Gear Solid 3 Remake has plenty of collectibles, all scattered around the area. Always keep a keen eye to pick up on the highlights to get the collectibles.