Cumulo is always quick to come to True when she says its name. It doesn't hesitate to bring True wherever she needs to, even though True usually asks it to bring her to The Wishing Tree. It doesn't speak much, but it usually tells True "hi" upon its arrival.
Cumulo is a cloud composed of three different sections. Its center is where its face is located, and it has two smaller clouds on each side. It has blue eyes and slightly blushing cheeks.