When a player set a Pikachu as a buddy, it stays by an avatar's foot. By walking 10 or more distance, a player can get Pikachu sheet on shoulder.
Some small size Pokemon can sit on an avatar's shoulder. Unlike Pikachu, they can be on a player's should just be set as a buddy.
Large Pokemon, such as Snorlax cannot be on shoulder.
Best Pokemon for fighting against Exeggutor