In the Anime
Morikamitchi is the god of Patchi Forest. He doesn't talk much and likes to bath in hot springs. He often hides in the trees and disappears without a trace. He is the one who guided Mametchi, Memetchi, Kuchipatchi, and Lovelitchi when the Kuchipatchi of Truth called for them.
He speaks words of wisdom. For example, in the episode Kuromametchi Finds His Coolness, Morikamitchi helps Kuromametchi out of the water when he almost drowns. As if knowing Kuromametchi was on a quest for coolness, Morikamitchi tells him, "Even the little rivers can transform into a big ocean."
Morikamitchi is stout and deep green with a bushy beard. He has small black eyes and you cannot see his mouth. He has a tiny bit of wavy hair on his head.
Mori means forest, presumably as in Patchi Forest, and kami means god. So, morikami means god of the forest.