There is sometimes a problem when you find a person in a workplace that enjoys to target one person and humiliates him/her in public (in front of other coworkers).
The person for example points that the target "does not know any better", "is a little bit of a person", changes the last name of the target to a joke to laugh at with the rest of coworkers...
Is there a guide on how to professionally yet efficiently deal with difficult personalities who cannot be avoided (in the workplace for example)? How could the manager (third-person) deal with this scenario in case it happens within his/her team?