Lie for the company. This is a clear ethical violation, and it can also have legal consequences. If an employee is caught lying on behalf of their company, they could be fired and/or sued.
Take the blame for their mistakes. This is a form of scapegoating, and it is never fair to ask an employee to take responsibility for something that they did not do.
Work during their breaks. Employees are entitled to breaks for a reason. They need time to rest and recharge, so they can come back to their work refreshed and productive.
Work when they are sick. Employees should not be asked to come to work when they are sick. They are more likely to spread their illness to their coworkers, and they are also more likely to make mistakes.
Share confidential information. Employees are often privy to confidential information about the company or their clients. Bosses should never ask employees to share this information with anyone else.
Talk about each other. Bosses should never ask employees to gossip about each other. This can create a toxic work environment and can damage employee morale.
Do personal favors. Bosses should never ask employees to do personal favors for them. This can create a power imbalance and can make employees feel uncomfortable.