After you catch 150 pokémon in the Kitakami Dex, Perrin tells you about the Bloodmoon Beast.

Learn About the Bloodmoon Beast

After you have caught 150 or more pokémon in the Kitakami Pokédex, talk to Perrin in Mossui Town. Afterward, talk to her again to battle her. She has a level 68 Noctowl and a level 70 Leafeon. You get 3920 Pokédollars for winning.

Afterward, Perrin tells you about an Ursaluna called the Bloodmoon Beast. She says it has been seen northeast of Oni Mountain, in the Timeless Woods.

Meet Perrin at the Timeless Woods

The Timeless Woods are in the northeastern part of the land of Kitakami. Go to the quest destination in the southeastern part of the Timeless Woods to find Perrin. Approach her and there will be a cutscene.

Defeat or catch the level 65 Ariados that attacks. Afterward, talk to Perrin at the tent. She asks you to photograph 10 pokémon that appear in the Timeless Woods on foggy nights.

Begin a Survey

If you're ready, talk to Perrin and you will wait in the tent for a foggy night.

Then walk around the area and look for pokémon. You can't use the camera while crouching, and the camera has no zoom, so just slowly get as close as you can, then open the camera and take the picture. You need to take pictures of ten different pokémon, so make sure to explore the area thoroughly. Pokémon can also be found in trees and caves.

After you have taken pictures of ten different pokémon, Perrin asks if you're ready to meet the Bloodmoon Beast. If you say yes, there will be a cutscene. Then you will battle the Bloodmoon Beast. You can't catch it, so just focus on defeating it. It will use Calm Mind, increasing its Sp. Atk and Sp. Def, so it could be helpful to bring a pokémon that knows a move that eliminates stat changes. It attacks with Earth Power, so it could be helpful to bring Flying-type pokémon since they're immune to that move.

After you defeat the Bloodmoon Ursaluna, you can catch it. The catch is guaranteed to succeed, so use whichever type of pokéball you like. Afterward, there will be a cutscene.

Meet Perrin in Mossui

Go back to Mossui Town and talk to Perrin. She gives you a Choice Scarf, and a Hisuian Growlithe.