Arkham Horror Dice Set: Black & Green: - Rules of Play says:
Prepare yourself for a new weapon in the ongoing fight to keep the streets of Arkham safe!
The Arkham Horror Dice Set contains five high-quality, crafted, polyhedral dice designed and created by Q-workshop company on license of Fantasy Flight Games. They are cast from hand-carved original sculpts, and feature ornately detailed faces as well as Elder signs on the "5" and "6" sides to indicate successes.