While no human has actually seen a Cherub or Seraph they are described in the Bible scriptures here:
The Cherubim:
Exod 25:20 The cherubim shall spread out their wings above, overshadowing the mercy seat with their wings, their faces one to another; toward the mercy seat shall the faces of the cherubim be.
1 Kings 6:27 He put the cherubim in the innermost part of the house. And the wings of the cherubim were spread out so that a wing of one touched the one wall, and a wing of the other cherub touched the other wall; their other wings touched each other in the middle of the house.
Ezek 10:5 And the sound of the wings of the cherubim was heard as far as the outer court, like the voice of God Almighty when he speaks.
Ezek 10:8 The cherubim appeared to have the form of a human hand under their wings.
Ezek 10:16 And when the cherubim went, the wheels went beside them. And when the cherubim lifted up their wings to mount up from the earth, the wheels did not turn from beside them.
Ezek 10:19 And the cherubim lifted up their wings and mounted up from the earth before my eyes as they went out, with the wheels beside them. And they stood at the entrance of the east gate of the house of the LORD, and the glory of the God of Israel was over them.
Ezek 11:22 Then the cherubim lifted up their wings, with the wheels beside them, and the glory of the God of Israel was over them.
The Seraphim:
Isa 6:2 Above him stood the seraphim. Each had six wings: with two he covered his face, and with two he covered his feet, and with two he flew.
The Angels/Messengers of God:
In God’s word the Bible you will find no description of an Angel having wings or being a Seraphim or Cherubim and in the following verses you will note that humans who saw angels did not describe them as having wings and in fact mistook them often as fellow humans.
The men of Gomorrah did not realize the men of lot were angels:
Gen 19:5 And they called to Lot, “Where are the men who came to you tonight? Bring them out to us, that we may know them.”
Here Gideon did not immediately realize he was speaking to an angel of the Lord:
Judg 6:13 And Gideon said to him, “Please, sir, if the LORD is with us, why then has all this happened to us? And where are all his wonderful deeds that our fathers recounted to us, saying, ‘Did not the LORD bring us up from Egypt?’ But now the LORD has forsaken us and given us into the hand of Midian.”
Judg 6:22 Then Gideon perceived that he was the angel of the LORD. And Gideon said, “Alas, O Lord GOD! For now I have seen the angel of the LORD face to face.”
Here it is plainly said that you may not know if it was an angel (no wings in their appearing to humans):
Heb 13:2 Do not neglect to show hospitality to strangers, for thereby some have entertained angels unawares.
Here again no wings are used in the description:
Matt 28:1-4 Now after the Sabbath, toward the dawn of the first day of the week, Mary Magdalene and the other Mary went to see the tomb. And behold, there was a great earthquake, for an angel of the Lord descended from heaven and came and rolled back the stone and sat on it. His appearance was like lightning, and his clothing white as snow. And for fear of him the guards trembled and became like dead men.
While we do not know the true appearance of these entities as they are in the spirit realm, all their descriptions show they are not the same.