Professor Willow’s Assistant Pikachu Weakness in Pokémon GO

Professor Willow’s assistant Pikachu made its Pokémon GO debut during Professor Willow’s birthday celebration on July 21, 2026. Pokémon GO’s official announcement lists Field Research, Timed Research, snapshot surprises, and raids as ways the costumed Pikachu could appear. It also says event Timed Research must be completed and claimed by July 27, 2026, at 8:00 p.m. local time. Read the official announcement.

Use this page for the type-chart question behind searches such as “Professor Willow’s assistant Pikachu weakness.” It separates the event facts Pokémon GO has announced from our matchup interpretation, so it does not assume an unconfirmed moveset, raid tier, shiny rate, or battle role.

Official event facts vs. Type Matchup planning

Officially confirmed: Professor Willow’s birthday celebration was scheduled for July 21 from 10:00 a.m. to 8:00 p.m. local time. The official announcement names Field Research, Timed Research, snapshot surprises, and raids for Professor Willow’s assistant Pikachu. It says the free Timed Research rewards must be claimed by July 27 at 8:00 p.m. local time.

Type Matchup planning: The official announcement does not provide a special moveset, raid tier, stats, or a separate battle typing for this costumed Pikachu. The weakness guidance below is our type-chart reading of the usual Electric-type Pikachu matchup. Check the live Pokémon GO encounter and its available moves before spending items or selecting a specific raid or PvP counter.

What is Professor Willow’s assistant Pikachu weak to?

For the standard Electric-type matchup, begin with Ground attacks:

• Ground: super effective against Electric in the standard type chart. This is the first attacking type to check when you need a type-only answer to Pikachu.
• Electric: does not deal extra damage to another Electric type in the standard chart, so it is not the efficient type advantage to seek here.
• Flying and Steel: Electric resists both of these defensive types in the standard chart, so they are useful to review when considering what may take an Electric hit more comfortably.

Pokémon GO does not use the main-series multipliers exactly, and it does not handle type immunities in the same way. For the game-specific context, see the Pokémon GO type chart. Then use the Ground type guide, Electric type guide, or the type matchup calculator to compare a candidate counter’s typing.

Event checklist before July 27

The official announcement makes one deadline especially important: event Timed Research tasks and rewards must be completed and claimed before July 27, 2026, at 8:00 p.m. local time. The announcement also notes Field Research rewards that can include PokéCoins, Lucky Eggs, and additional assistant Pikachu encounters.

Before that deadline:

1. Review the available Timed Research and claim completed rewards.
2. Check Field Research and snapshot encounters in your local game before assuming a particular encounter method is still active.
3. If you are choosing a battle answer, start with a Ground-type option and confirm its moves in Pokémon GO.
4. Compare the full matchup in the Pikachu type page and the team weakness calculator.

What this guide does not claim

The official announcement says a Shiny assistant Pikachu is possible, and it mentions team leader–specific Special Backgrounds. It does not establish exact Shiny odds, the best counter Pokémon, the exact moves available, or a PvP ranking. Those are live-game or format-dependent questions, not official event facts in the announcement. This guide therefore gives a type-chart starting point rather than a promised Pokémon GO battle result.

Professor Willow’s assistant Pikachu FAQ

When did Professor Willow’s assistant Pikachu appear in Pokémon GO?

Pokémon GO’s official announcement scheduled the birthday celebration for July 21, 2026, from 10:00 a.m. to 8:00 p.m. local time. It introduced Professor Willow’s assistant Pikachu through Field Research, Timed Research, snapshot surprises, and raids.

What is Professor Willow’s assistant Pikachu weak to?

For the usual Electric-type Pikachu matchup, Ground is super effective in the standard type chart. Pokémon GO has its own damage values, so verify live moves and the battle format before treating a type advantage as a complete counter recommendation.

When must the Timed Research rewards be claimed?

The official announcement says the event Timed Research tasks and rewards must be completed and claimed by July 27, 2026, at 8:00 p.m. local time.

Does the official announcement list a unique battle typing or moveset?

No. The announcement describes the costume, event appearance methods, possible Shiny encounter, and possible Special Backgrounds, but it does not specify a separate type, moveset, raid tier, or PvP performance for the costumed Pikachu.