Text from Kamen Rider Magazine. There is some new information.
Greed's are able to create Yummy's through Cell Medals. (Silver Cell Medals are the power sources of weapons used by OOO)
There are 2 stages of a Yummy.
1. Yummy(ヤミー): Greed's create these Yummies by throwing a Medal into the back of a human beings head. A hole is then created, when a Cell Medal is put inside a Yummy will be created.
2. OOYummy(○○ヤミー): When a Yummy absorbs human desire they evolve into this stage.
