Same guy pre- and post-Crisis, as far as I know; the transformation from guy-in-costume to guy-who's-actually-a-snake was a Neron upgrade during Underworld Unleashed. I don't know that he's actually fought Batman much post-Crisis, if ever... I don't know that he's actually fought anyone post-Crisis outside of UU and Kate killing him... but he's as likely to come up in "obscure Bat-villain bingo" as Jane Doe is, after all. I mean how many times has she done anything? And she can't even claim Wonder Woman and Batgirl as defeated foes.