Simple

When one of this Pokemon's stat stages is raised or lowered, the amount is doubled.

5 Pokémon have this ability

#322

Numel

FeuSolHoenn

#399

Bidoof

NormalSinnoh

#400

Bibarel

NormalEauSinnoh

#527

Woobat

PsyVolUnys

#528

Swoobat

PsyVolUnys