Latest Pokemon GO information about Forretress Bug and Steel pokemon. Pokemon Go Generation 2: Bug Type Pokemon are countered by Fire Type. For Example, Typhlosion (Fire type) will deal increased damage to Forretress when using any Fire Moves against him in Gym Battles.

Additionaly, since this Pokemon is also a Steel Type.

It will suffer increased damage from Fire Type Pokemon, such as Typhlosion or if damaged by any Fire Type Moves.

However, it will also take decreased damage when attacked by Grass, Psychic, Dark, Fairy, Ice and Rock moves.