It was both a literal and figurative serpent.

https://www.etymonline.com/word/serpent

This is reconstructed to be from PIE *serp- "to crawl, creep" (source also of Sanskrit sarpati "creeps," sarpah "serpent;" Greek herpein "to creep," herpeton "serpent;" Albanian garper "serpent").

Serpent and snake now mean precisely the same thing ; but the word serpent is somewhat more formal or technical than snake, so that it seldom applies to the limbless lizards, many of which are popularly mistaken for and called snakes, and snake had originally a specific meaning. [Century Dictionary, 1902]

Serpent, therefore, does not directly refer to a snake, though there was a snake in the story. The Serpent is in reference to that which creeps -- the temptation which crawls about the mind steering us towards sin.

The story of Adam and Eve is to be taken BOTH literally and figuratively, as both events did transpire.

The personification is of utmost importance in the matter.

When Jesus tells a Parable, are we to assume he is lying when he said "there once was" and not take him at his word that he is recalling actual events? No, he's not lying because while he might not be pointing out one particular event with which he can cite names and a time and place, he is talking about the State of Man and his Doings.

There is Truth in the act and the relationships, so that they are their own thing. The moral Truths are a real thing though they lack a corporeal or physical form. They manifest in the Doings of man.

Genesis DID happen as described, and a literal serpent DID speak to Eve. But what happened in the physical also happened in the spiritual. The Creeping thing entered Eve's ear and mind and convinced her to partake of the fruit.

Concerning the fruit, what matters most? That it was a physical fruit which would bring with it the sting of death? Or that God told Man not to eat of the fruit of the tree yet he did anyways?

BOTH are of equal importance. The physical fruit made man mortal while the spiritual fruit of the forbidden tree made Man confront his shame, and so he hid his loins from his Father. Why would Adam hide his loins? God made his penis, so why the shame?

Because the groin represents Adam's offspring. "What you have wrought!"

Adam was hiding his groin because his groin wasn't just for making babies, it was for REPRODUCING in all its forms and glory.

Adam, when he willingly partook of the fruit realized what he had wrought -- what foul thing he birthed into the world, and look upon himself in shame that he brought it about.

In Genesis, we must understand, the physical and spiritual realms were never more in sync. Every action and symbol immediately gave effect in the spiritual realm.

Lucifer was the first angel to fall, and him doing so birthed new words and concepts into Creation by Adam's hand.

Man alone can act in the Authority of God to bring about New Things. Man alone is destined to go and name all that which God has made.

What do you think was meant by Genesis 2:19?

https://www.biblegateway.com/passage/?search=Genesis%202%3A19&version=GNV

19 So the Lord God formed of the earth every beast of the field, and every fowl of the heaven, and brought them unto the [a]man to see how he would call them: for howsoever the man named the living creature, so was the name thereof.

Man's charge by God, that one part of His Divine Spark within us, manifests in our ability to bring about NEW things. To bring into the Universe concepts and ideas that physically and spiritually have yet to exist.

When we invent, when we Create, we act as God has intended us. When Man brought into the world Slander, Rebellion, and the Adversary, it was named thusly.

Lucifer was the catalyst, but the reaction took place in the flawed Heart of Man.

Jesus' role is to come about and clean the Heart of Man and squelch all the wrong which Man was tempted to do. In that way, he washes away the Words of Man which Man has grown to be ashamed of -- of which Man has covered his Loins in despair.

You cannot take the physical without the spiritual when we talk about Genesis. The physical events and the spiritual events are coupled together. The nature of the allegory is the Word -- as it is a story told in Nature as well as in the Mind of Man who babbles with words of his own making instead of in the Language of God, which is the Language of Nature and the relationships between all things.