"Elements of the mountains. Their name means "lurking souls." They are sometimes identified with the kodama. Sudama are born from the pure essence of the rocks and trees of lush, green mountains where few humans have set foot. They are said to live in huge, ancient trees and giant, ageless boulders. Sudama never cause trouble, and sometimes take human shape in order to watch over their mountain homes. Tradition holds that when you are in the mountains and get the feeling you are being watched, it is a Sudama watching you."
—Shin Megami Tensei IMAGINE Compendium
Sudama appear regularly on Shibuya field and the Shibuya-based Quartz instance. Within Quartz, they are notable for a variant that uses a powerful suicide attack.
"A spirit of rivers and mountains in Japanese lore. Over long periods of time, they dwell in trees and rocks. They are not evil, but they watch over the mountains and appear as humans or supernatural wonders to warn people" - Strange Journey Compendium