Call of Cthulhu uses any standard 7-dice set.
For the vast majority of Call of Cthulhu you'll only be using percentile dice, but at times in Cthulhu you'll need to use other dice from the 7-dice sets, for rolling damage, stat checks, and determining the ever-present sanity losses. While any 7-dice set will work for Call of Cthulhu, there are unique Call of Cthulhu dice made by Q-Workshop - as well as some awesome unique Cthulhu leather dice bags.
These Cthulhu dice feature an awesome Cthulhu theme, and here at Awesome Dice we're a big fan of owning dice that are appropriate to each game that we play. But we do think that having Cthulhu dice is a bigger deal in Call of Cthulhu than most other games. After all, Cthulhu is a game all about mood and atmosphere, and every little touch adds to that and heigtens the feeling that this is more than just another hack & slash game.
You can buy the specialty Cthulhu dice & dice bags or buy any 7-dice set and dice bag and be ready for horror and the descent into madness. Cthulhu ftagan!