A full Yorick skin gallery, plus the practical point: some skins change the silhouette enough to matter in a fight.
Before the cosmetics: Yorick is a fighter at 175 attack range whose job is to trade repeatedly, survive the return damage, and win the third exchange rather than the first.

Yorick has 9 skins, excluding chromas. The art below is the in-client splash.
Skins change no numbers. They are not therefore free of consequence — a skin that alters the silhouette or recolours an ability changes how quickly an opponent reads what you just cast.
That cuts both ways, and it is the honest reason some players keep the base skin on champions they take seriously.
The Cursed Horde: Yorick can summon Mist Walkers to swarm and attack nearby enemies.
Yorick deals bonus damage on his next attack and heals himself. If the target is a champion or large monster or if the target dies, a grave will be dug.
Yorick summons a destructible wall at target location that will block enemy movement.
Yorick throws a globule of Black Mist that reduces armor, damages, slows and marks enemies. Summoned units gain move speed when moving towards marked targets.
Yorick summons the Maiden of the Mist that causes Yorick's attacks against the Maiden's target to deal bonus damage. The Maiden will also automatically raise Walkers from dead enemies.
The last survivor of a long-forgotten religious order, Yorick is both blessed and cursed with power over the dead. Trapped on the Shadow Isles, his only companions are the rotting corpses and shrieking wraiths that he gathers to him. Yorick's monstrous actions belie his noble purpose: to free his home from the curse of the Ruination.
Skins are tied to the account, not to you. Anything bought on a smurf stays on the smurf — worth knowing before spending real money on one.
Full Yorick page — abilities, stats and every skin →