We had a Brown snake that big in our warehouse at work just a couple of weeks ago. Scary thing was I was only a couple of metres away from it at one stage, not long before it was discovered moving under a pallet by one of the warehouse staff.
Ended up having to call in a snake catcher who made catching it look like childs play!
We later checked the security camera footage and saw it just wonder in through the receiving gate undetected earlier that afternoon. Cheeky bugger.