Ruined King: A League of Legends Story

There are 30 total types of fish in the game to catch for this achievement, and over a dozen fishing spots that you can use to catch them. I'm not sure if every fish is available in every spot, but this guide has a listing of exactly where that writer found each fish, so use that if you're struggling. You'll need to purchase the Mechanical Catching Apparatus rod and Fishmonger's Secret lure from the Black Mark Vendor (you'll need 76 black marks total) to catch the rarest of these fish. If you've caught all the fish in a location and didn't get something you were expecting, don't fret - go to a rest point and return to respawn everything for another chance - it's RNG, baby!
 

To actually perform the fishing mini-game, cast with  and then hold that down and push the  toward the dock to fight the fish. The outside bar represents the fish's stamina and the inside bar represents your line strength. You need to deplete the outside bar and get the fish to the dock before the inside bar depletes or the fish will get away.