Skull Bash

Skull Bash is a Normal-type move introduced in Generation 1.

Values by generation

From PokeAPI's change history. Up to Generation 3, physical or special depends on the type. Highlighted cells changed from the previous generation.

Generation	Type	Category	Power	Accuracy	PP	Priority
Generation 1	Normal	Physical	100	100	15	+0
Generation 2	Normal	Physical	100	100	15	+0
Generation 3	Normal	Physical	100	100	15	+0
Generation 4	Normal	Physical	100	100	15	+0
Generation 5	Normal	Physical	100	100	15	+0
Generation 6	Normal	Physical	130	100	10	+0
Generation 7	Normal	Physical	130	100	10	+0
Generation 8	Normal	Physical	130	100	10	+0
Generation 9	Normal	Physical	130	100	10	+0

Gold / Silver · Crystal	1st turn: Prepare 2nd turn: Attack
Ruby / Sapphire · Emerald	Tucks in the head, then attacks on the next turn.
FireRed / LeafGreen	The user raises its DEFENSE in the 1st turn, then attacks in the 2nd turn.
Diamond / Pearl · Platinum · HeartGold / SoulSilver	The user tucks in its head to raise its Defense in the first turn, then rams the foe on the next turn.
Black / White · Black 2 / White 2 · X / Y · Omega Ruby / Alpha Sapphire	The user tucks in its head to raise its Defense in the first turn, then rams the target on the next turn.
Sun / Moon · Ultra Sun / Ultra Moon · Let’s Go, Pikachu! / Let’s Go, Eevee! · Sword / Shield	The user tucks in its head to raise its Defense stat on the first turn, then rams the target on the next turn.

Red / Green · Blue · Red / Blue · Yellow	TM40
Mega Dimension	TM146

All versions combined; see each Pokémon's page for game-by-game details.

Sources : PokeAPI (moves, move_changelog, move_flavor_text, pokemon_moves, machines)