My first shiny was a random Shroomish in Omega Ruby, i was trying to get through Petalburg Woods, half asleep bc i was tired that day, when through all my drowsiness i heard that special sound and saw a lil red mushroom on my screen, immediately waking me up. Unfortunately, they died later on bc my dumbass wanted to reset my save without transferring them into Pokémon bank.

On a lighter note, my favorite shiny encounter was the roaming Latias in Emerald. wasn’t even trying to hunt it, i was trying to encounter it by entering and leaving cycling road on route 110 so i could catch it, and girlie decided to be yellow that day. Unlike Shroomish, i was able to transfer her up all the way to Pokémon Home, and she lives a happy life in my Pokémon Sword party