Have you ever met someone who is just plain toxic. They huddle with one or more people in their environment and whisper and speculate about events that are what they are, the decisions made by the boss or some other authority. Ultimately, they succeed in working everyone up into being angry and dissatisfied, and pretty soon everyone in the group is feeding each others dissatisfaction.
Now here's the fun part - have you ever included such a person in one of your stories? I haven't. I never thought of it before, to be honest. Then again, I generally don't write using the right kind of environment for such a character. Such a person needs a group of people to work or socialize with. They also need an authority who dictates their basic day.
Such a character needs to be dissatisfied, but not so much so that he or she is willing to quit or move on. They don't want to quite. They don't want to move on, not really. They want to be unhappy and they want company. From there, they need something to complain about. Not enough pay. Too long hours. Not enough authority or responsibility. They could do the job better. Whatever the excuse.
Such a character might do some serious stirring in your story. Give it a thought and tell me what you think. I don't believe I've ever read a story where such a character was included, not even as a background character. Have you?