Wormadam's best moveset in Pokémon GO is Tackle and Struggle, with 6.68 damage per second, and it can deal 153.6 damage before Wormadam faints. This is true when battling in neutral weather.
All Wormadam movesets ranked
Here is a complete list of Wormadam movesets in Pokémon GO, ranked by their DPS and TDO. You can change the weather and the opposing Pokémon.