A Perfect Pickling Stone is the 12th request in Pokémon Legends: Arceus. Because of the location required for this request, it’s easiest to complete after you’ve progressed a bit through the main story and defeated your first Alpha Pokémon. To find the request, enter Galaxy Hall and head to the second floor. A woman named Radisa needs you to help her find a Pokémon that can assist her as a stone for the jars she uses for pickling, and that Pokémon is Geodude. Thankfully, Geodude is easy to track down.
Once you’ve defeated your first Alpha Pokémon, you’ll have unlocked a new basecamp in the Deertrack Heights location of the Obsidian Fieldlands. Geodude hangs out in the very immediate area. Leave Juibilife Village and select the Heights Camp as your destination when setting out for the Obsidian Fieldlands. You’ll barely need to walk down the path in front of you before running into a Geodude.
Being a Ground/Rock-type hybrid, Geodude is weak to quite a few Pokémon attacks. Pokémon like Oshawott or Buizel are a great choice for battling it thanks to the advantage of their Water-type moves, as are Grass-type Pokémon like Rowlett or Bug-type Pokémon like Kricketot. Geodude can also be captured by throwing a Pokéball while hiding from its line of sight using stealth. When you’ve captured a Geodude, return to Radisa to complete the request.