The Pokémon GO evolution of Eevee with a white collar and a light-blue body is Vaporeon. It is a Water-type Pokémon whose design combines aquatic features with the familiar fox-like shape of Eevee.
Vaporeon was introduced in the original Pokémon games as one of Eevee’s three available evolutions, alongside Jolteon and Flareon. In Pokémon GO, players can evolve Eevee into Vaporeon using 25 Eevee Candy, although the result is normally random unless a nickname-based evolution trick is used once for each evolution.
Vaporeon is often confused with other Eeveelutions because all share Eevee’s basic body plan. Its blue coloring, fish-like fins, mermaid-style tail and white neck frill distinguish it from yellow Jolteon and orange Flareon. Its Pokédex lore says it developed fins and gills that allow it to live in water.
In battle, Vaporeon is known for its high HP and useful Water-type moves, making it a popular early-game choice for many Pokémon GO players.