Monster Pack – Cthulhu includes a new monster — Cthulhu, in case you couldn't guess — as well as eight evolution cards for use with King of Tokyo and eight evolution cards for King of New York. Fifteen cultist tokens are also included for card effects.
The Cthulhu Monster Pack is compatible with King of Tokyo and King of New York, as well as their expansions. Cthulhu’s Evolutions work like the Evolutions in King of Tokyo: Power Up! And King of New York: Power Up! To play with Cthulhu’s Evolutions, you need the Power Up! expansion for whichever base game you have.
This is not a standalone game. You need King of Tokyo or King of New York to play this expansion.