They're the one with the "Zols, Zols, Zols" speech bubble above them. There are three parts to the 'A Curious Child' side quest. The first requires you to present a Zol Echo to the child in Hyrule ...
Zol Echo Armed with a monster of your own, you can now summon up to three Zols to fight for you, and direct them to attack specific monsters by targeting them with ZL. As you explore this side of ...
This is the second quest you get from the young boy, who is obsessed with Zols, creatures that roam around Hyrule. His last request requires a bit more work; it's a good thing we're here to impart ...
Then, in the next room, you need to summon an Echo to defeat all of the shadowy Zols (the Peahat works very nicely). Outside, hop up onto the higher platform, then go down the ladder on the island ...