Buddy Pokémon

Buddy Pokémon is a game mechanic that allows trainer to choose a one Pokémon from their collection that after walking certain distances will reward trainer with specific candy.

The chosen Pokémon will appear next to its trainer's avatar on the profile screen. The Buddy will be able to be swapped out with another Pokémon at any time, 20 times per day. A Buddy cannot be assigned to a Gym nor transferred.

An elevated experience Buddy Adventure was introduced on December, 2019. Trainers can play with their Buddy and increase their Buddy Level.

Buddy Pokémon rewards
Each Pokémon that is assigned as Buddy has specific amount of kilometers to be walked after which trainer is rewarded with a candy. There are currently four different distances to be walked for a candy reward:
 * 1 kilometers - distance mostly for common Pokémon and their families,
 * 3 kilometers - distance for most of Pokémon and their families,
 * 5 kilometers - distance mostly for rare Pokémon and their families,
 * and 20 kilometers - distance for Legendary Pokémon.

Buddy Pokémon types
Also every Pokémon has its specific type of Buddy Pokémon that defines what size and where is placed Buddy relatively to trainer. There are five Buddy Types:
 * Medium - Buddy Pokémon is placed to the right of a trainer and it is smaller or equal to trainer's size,
 * Big - Buddy Pokémon is placed behind to the right of a trainer and it is bigger than trainer,
 * Shoulder - Buddy Pokémon is small enough that can be placed on trainer's right shoulder,
 * Baby - Buddy Pokémon is small enough to be held in hands of trainer,
 * and Flying - Buddy Pokémon flies, floats or hovers behind the trainer. Unlike four other types of Buddy Pokémon, this type doesn't define any range of Pokémon's size so Pokémon's size might differ. Most of Flying-type Pokémon have Flying as type of Buddy Pokémon as well, but not all of them.

After Buddy Adventure update, Flying Buddies differ from the other types of Buddy with flying over the map instead of running about.

Daily Activities and Affection Hearts
Engaging in Activities allows temporary increase of Buddy Pokémon's mood and rewards Affection Hearts. The Today's Activities in Buddy Profile screen lists each way to interact with the Buddy. Each time Trainers engage in a listed activity with their buddy, the hearts will turn from gray to pink, indicating a heart is earned in that category. Daily Activities reset at midnight local time.

Type of Buddy Activities:
 * Walk together: Buddy Pokémon will appear when hunger meter is full until it is fully depleted. One Affection Heart is earned for each 2 km walked, up to three per day.
 * Give your buddy a treat: Feeding Buddy fills up the hunger meter. One Affection Heart is earned when you fully fill up the hunger meter.
 * Play together: Play with Buddy in AR mode until light is seen from the buddy.
 * Battle together: Use the Buddy in Gym, Raid Battle, Trainer Battle, or Team GO Rocket.
 * Take a snapshot: Take a photo of the Buddy.
 * Visit a new place: Visit a Gym or a new PokéStop.
 * Bonus: Bonus Heart is earned when Buddy gives a present or souvenir, or Trainers visit a PokéStop or Gym that Buddy wants to visit. This activity is only visible upon receiving an Affection Heart on this category.

Mood
Interacting with Buddy improves their mood. It decreases over time. Swapping buddies reset it back to Normal. Excited is the most positive mood, which doubles the Affection Hearts that could be earned, except in the Bonus category. The candy walking distance is halved when excited. Extra earned Affection Hearts remain even if the Buddy is no longer excited.

Type of Moods and required points:
 * Tired: 0
 * Dull: 1
 * Normal: 2
 * Happy: 4
 * Smile: 8
 * Fun: 16
 * Excited: 32

Buddy Levels
Earning Affection Hearts increases Buddy Level. Similar to Friendship Levels, they unlock special perks.

Buddy gifts

 * To be added.

Catch assist

 * To be added.

Souvenirs

 * To be added.

Trivia

 * There is an Easter Egg about Buddy Pokémon. Initially when a Pikachu is assigned, it will show up on the ground beside the trainer. However, if a trainer walks a distance of 10km or more, the Pikachu will appear on top of the trainer's shoulder.
 * There is significant relation between Buddy distance for candy reward of specific Pokémon and what egg it hatches from, as:
 * Pokémon that hatch or originally hatched from 2-km Eggs have to walk 1 km for candy reward,
 * Pokémon from 5-km Eggs have to walk 3 km for candy reward,
 * Pokémon from 10-km Eggs have to walk 5 km for candy reward
 * and Legendary Pokémon that don't hatch from any egg have to walk 20 km for candy reward.
 * Shadow Pokémon or even fainted Pokémon can be assigned as Buddy Pokémon.
 * Since the introduction of Buddy Adventure, swapping Buddy Pokémon no longer resets progress toward earning Candy.
 * Best Buddy medal was introduced on March, 2020. It requires the Trainer to have 1, 10, and 100 Best Buddies.