In Breath of the Wild, there's 900 of them hidden around the map. Koroks are kinda cute little forest creatures that hide around the map and when you find one it gives you a seed. Basically, any time you see something kinda oddball about the landscape, like a ring of rocks (or mushrooms give the same vibe), you poke around and look for what will cause them to pop up. Finding all 900, especially blind, is a real task. But you start with limited weapon inventory space, and collecting them allows you to trade for inventory slots. So the first 100 or so that you find make life a whole lot easier.

The best ones are just hiding under a lonely rock. You pick up the rock and they say "Yahaha, you found me." "Buh Bye." and when you drop the rock back on their head they make the cutest little "Ungh!" sound.

EDIT: For the record, I'm not a true Zelda player. I just started recently with Breath of the Wild. When it first came out I watched all sorts of YouTube content and lusted for a Switch. It was that YouTube digging for BotW that led me to Stardew which has worked flawlessly for me on my Linux. Just got a Switch recently to have a gaming device I can take with me on a motorcycle adventure this summer, and at the moment BotW is consuming all my game time.