Leif, Duna, and Tarush are arguing over Burmy and they want you to show them one as proof.

The Request

Talk to Leif in Jubilife Village to accept the request.

Catch a Burmy

Burmy can be found by throwing a partner pokémon at a shaking tree.

Catch the Other Forms of Burmy

To complete the request, you need to show Leaf Cloak Burmy, Sand Cloak Burmy, and Trash Cloak Burmy, so be sure to catch at least one of each form.

Show Burmy's Complete Pokédex Entry

After you complete Burmy's Pokédex Entry, talk to Leif, Duna, or Tarush to proceed.

Reward

As a reward, you get 1 Leaf Stone, and 3 Exp. Candy M.