Shamsiel (also spelled Shamshel or Shamshiel) was the 16th Watcher of 20 leaders of 200 fallen angels. He is mentioned in the Book of Enoch. Shamsiel, which means “sun-of-God”, is fitting as Shamsiel was believed to have taught men how to recognize the sun signs during the time of Jared and Yered. Shamsiel and Shamash may have some mythological connections.
Shamsiel is believed to have led 365 legions of lesser Angels in the Zohar. It is also said that God assigned him to guard the Garden of Eden after Adam & Eve were expelled. This is similar to the cherubim. Sources differ on whether Shamsiel is a fallen Angel.