The ambush stones from Pinkerton’s Pile aren’t actual physical items. It is instead when Crim appears suddenly under an item your dragon just moved and asks, “What’re you doing?” in a rather sinister manner. Your dragon then figuratively (maybe even literally, depending on flight) shits bricks and flies/runs off, but with imparted knowledge of, “So that’s how ambushing works.” They are then free to teach a dragon this technique.
gogoboi: My Yoona is the prettiest princess in the whole world! I gave her an Instagram camera as birthday present and asked her to create an account and share more pics with us. She said yes and let us wait. #snsd #yoona #happiness