I assume by your post that you are one of the people who thus coworker is speaking badly of. Either that or you are a person who this coworker is speaking to ab

I assume by your post that you are one of the people who thus coworker is speaking badly of. Either that or you are a person who this coworker is speaking to about others. In either case, it can be uncomfortable. Have you thought about talking to your coworker directly? I know this may sound rough right now and I don't suggest being confrontational. Maybe just ask him out to lunch with you. Build a relationship. It's hard to be mean to a friend... You could become his friend. I had a similar situation recently with a coworker. At a company lunch I noticed this particular coworker was not invited to sit with anyone. I invited him over. We chatted about non-work things. Our relationship did improve. He's still overbearing and mean, but less so. Our relationship has improved. Also, are his evaluations actually incorrect? Sometimes people are mean and honest at the same time. Are the people he is speaking badly about actually completing work poorly? Is he having to pick up their slack? Does he have to work late or harder because of them? He is purely venting his honest frustration?