What to do with him regarding this behavior?
Based on the information you have provided, I believe you are in a classic no win situation. Going to HR would most likely not offer any relief, as actual employees have already attempted to alter his behavior with no success.
You have three options in my view:
- Tell your employer to find a new home for you.
- Just put your head down and do the work, ignoring the behavior.
- Find another place to work yourself.
Good luck with this situation.