The following is the list of all the champion skins inspired by popular culture in the client.

Source of Inspiration Skins
Alice in Wonderland
Alien vs Predator
Dr McNinja series
Dynasty Warriors series
Final Fantasy series
Grim Reaper
Gurren Lagann
One Piece
The Three Musketeers
Little Red Riding Hood
The Lord of the Rings trilogy
Magical girl series
Mortal Kombat series
Monster Hunter series
Robin Hood
Starcraft series
Star Wars series
Superhero / Supervillain
Warcraft series
X-men series