During the event, there was an increased frequency of Water-type Pokémon encounters in the wild. Pokémon like Magikarp, Squirtle, Totodile and even the elusive Lapras were easier to find in the wild. There was also a higher chance to encounter Pokémon from Johto in water biomes. 
Additionally, a new Magikarp Hat was available, in the hat section of the wardrobe, at no cost.
Following Pokémon were featured during the 2017 event and most of them were appearing more frequently in the wild: