Dig causes damage. On the turn it is used, your Pokémon digs
underground, where it is protected from most attacks. On the following
turn, your Pokémon emerges and causes damage. Outside of battle, Dig
immediately extracts you from most caverns and buildings, placing you at
the PokéCenter you most recently used.
Dig has one of the highest Average Damage ratings of all Ground
Because it is a Ground type attack, it cannot affect Flying Pokémon.