@hightor,
There's also the Gnostic interpretation which I'm reluctant to mention because of Greatest I am.
In that the serpent is acting on behalf of the true god, making sure they eat the apple in order to eventually achieve 'Gnosis.'
"God" is the demiurge reliant on stolen souls to exist which he needed to keep ignorant.
Obviously it's more bloody involved than that, but if you want more detail this is very good.