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