Before someone else adds it, there are two cases of a mortal being made an angel, though they exist in extra-Biblical Jewish lore, not the Bible (or Old Testament on its own for that matter).
One would be Enoch, the other would be Elijah (Elias). At any rate, both are said in the Bible to have been taken up physically by God, so that they never ‘died’ in a normal sense. The Bible leaves it at that, but Jewish pseudipigrapha states that Enoch became the angel Metatron and Elijah became the angel Sandalphon. Typical descriptions of the two have them as the ruler of angels, standing 500 feet tall and made of bronze and other odd descriptions that make them sound more like an angelic Paul Bunyan than something you’d see in a painting by Michelangelo.