Skull Bash is an offensive Normal-type move.
Skull Bash will raise the user's Defense by one level on the turn it is selected. On the following turn, Skull Bash will do damage, PP will be deducted from it, and it will count as the last move used. Once Skull Bash is selected, the user won't be able to switch out until it is disrupted or fully executed.
If Skull Bash is not fully executed, PP will not be deducted from it, and it will not count as the last move used. If the opponent uses Mirror Move during the turn that the user lowers its head, Mirror Move will copy the move that the user executed immediately before using Skull Bash (or fail if it can't).
Sleep, freeze, partial trapping, and flinching will pause but not disrupt the duration of Skull Bash.
Pokémon that learn Skull Bash
By leveling up