This category of angels does not seem to fall into an angelic type or rank from scripture. This does not mean that they are not powerful nor from God. They do God’s work as asked and carry out his bidding.
Hebrews 13:2 “Be not forgetful to entertain strangers: for thereby some have entertained angels unawares.”
Acts 12:15 “And they said unto her, Thou art mad. But she constantly affirmed that it was even so. Then said they, It is his angel.”
Not much else is said in scripture. However, we will get to this more when move through creation itself.