Seraphim, Serafim: (“Fiery Ones”). A class of angels first described in the apocalypse experienced by Isaiah in the Temple (Isa. 6). There are four seraphim, corresponding to the four winds. The appearance of the Seraf is truly awesome. It has six wings, sixteen faces, and is the height of all seven heavens combined. Serafim are born anew each day, rising from the river of light that flows from under the Throne of Glory (Sefer Hechalot). According to Enoch I, they are serpent-like. The Talmud counts Michael among the Serafim:
R. Eleazar b. Abina said furthermore: Greater is [the power] ascribed to Michael than that ascribed to Gabriel. For of Michael it is written: Then flew unto me one of the Seraphim, whereas of Gabriel it is written: The man Gabriel whom I had seen in the vision at the beginning, being caused to fly in a flight.... [one "flap" vs. two "flaps"]. How do you know that this [word] 'one' means Michael? — R. Johanan says: By a word association; [the words] 'one', 'one'. Here it is written: Then flew unto me one of the Seraphim; and in another place it is written: But, behold, Michael, one of the chief princes, came to help me (B.T. Ber. 4b)
The Zohar contains a section on angels, probably a Hekhalot text inserted into the teachings on creation, which briefly discusses Serafim.