The 15th-century Ethiopian text, "The Book of the Mysteries of the Heavens and the Earth" teaches that Michael took on the form of a star to guide the Magi to Jesus.
The Book of the Mysteries of the Heavens and the Earth: And Other Works of Bakhayla Mikâ’êl (Zôsîmâs) (trans. E. A. Wallis Budge; Lake Worth, FL: Ibis Press, 2004), 35
[SAINT MICHAEL LED THE MAGI AND BROUGHT THE ISRAELITES SAFELY THROUGH THE RED SEA]
And thou must not imagine that the MAGI came [to BETHLEHEM] after [CHRIST] was born, or that they rose up from their country two years before [Fol. 17b, col. 2] our Lord was born [of their own prompting], for MICHAEL in the form of the Star guided them. And it was he who brought out the HEBREWS [from EGYPT]. For when he smote the cloud there was rain. And the angels of the clouds pressed out the water and made it to fall [into the sea], and through the rain one thousand soldiers died. Then for three days and three nights there was bitter (or, freezing) cold, and one thousand men died through the cold. And the HEBREWS remained in the water three days and three nights, and then monsters of the water (or, sea) went forth and killed the EGYPTIANS. Some of these monsters were like lions, and some like leopards, and some like bears, and some like serpents (or, boa-constrictors) [Fol. 18a, col. 1]. And they all uttered horrible noises and the EGYPTIANS were terror-stricken, and before they reached the sea these monsters rushed to meet them.