The Cosmic River is a religion and philosophy followed by the river giants of Matarsah. The Cosmic River is believed to be a primordial waterway that carries the world along in its current. In the cosmology of its faithful, the Cosmic River is a cyclical entity - though sometimes worshiped as a deity, it is rarely personified as such. The fresh waters that feed rivers on the Material Plane are thought to originate from the Cosmic River, seeping through the earth until they flow freely once more, eventually making their way out to the oceans and then to the primordial river to begin the cycle anew. The river giants of Matarsah also believe that the passing Lifewaters collect their memories, taking them to the Cosmic River to proceed through to the Material Plane again when their recollections and knowledge would be useful to future generations.
Some non-giant scholars associate the Cosmic River with Taliash, but the giants themselves rarely do so.