In Buddhism, Nagas are snakes that hold a special place. It is believed that they are rain gods and protectors of the Dharma. Their images are often found decorating roofs and stairways of Buddhist temples.
This card depicts a famous story where the buddha was meditating and as it started to rain, a seven-headed Naga came up behind the Buddha and spread its hood open to protect the Buddha. The Naga didn't want to see the Buddha's meditation interrupted by the rain.