Many commentators (e.g. the Seforno) claim that the primordial serpent, the ??? in the Garden of Eden was none other than the Yetzer Hara.
i thought that was going after sm (name of the malach) went into the nachash
basically before he had sm he was a normal snake with tayvas but when he let it consume him he allowed sm to enter him whereby he became part and parcel of the yetzer hara
(if something isn’t clear please ask, im on my phone)