Niantic recently announced a special One Piece-inspired event featuring Straw Hat Pikachu for Pokémon GO. The event will take place from July 22 to July 29 and will mark the debut of this new hat-wearing Pikachu, which is inspired by the iconic hat worn by Monkey D. Luffy. A Straw Hat with a red ribbon avatar item will also be made available in the in-game Style Shop. In addition, in Japan, Monkey D. Luffy statues in the Kumamoto Prefecture will eventually serve as PokéStops, featuring artwork by Eiichiro Oda. Read on below for more details:
From July 22, 2019, at 1:00 p.m. through July 29, 2019, at 1:00 p.m. local time, this special Pikachu will appear in the wild, giving Trainers plenty of chances to add it to their crew. Pikachu’s kicky straw hat is perfect for keeping the burning sun at bay during these sunny summer months. If you want to coordinate your avatar’s outfit with Pikachu, there will be a matching straw hat available in the Style Shop.
Source: Official Pokémon GO blog