Ok, a rusty iron golem without poison cloud. Edit: No, seriously, there are ways around that. Eliminating the poison cloud ability and making the golem not able to charge is a way; also, making sure the party sees the golem long before (it's at the other end of a long corridor or room) it has a chance to charge the party; or the room has enough obstacles, like columns, to avoid being charged; or perhaps on another room there are clues or notes on the golem's instructions left long ago by the wizard so they can trick it into not attacking the party. There are a lot of options.