CarpeTools [Design]> Create> Irregular> Clouds...
Basically, this tool is used to create Abstract designs with patches of clouds. It Generates a soft cloud pattern using random values between the Primary and Secondary colors. When you apply the Clouds effect, the design on the active layer will be replaced. Therefore, need to add a new layer and generate clouds to give a special effect to the design.

Original design (left), design with cloud (right)