antagonizer
/æntəˈɡɒnɪsaɪzər/Definitions
1. noun
A person who habitually provokes or causes trouble for others.
“She was known as a master antagonizer at the office, constantly stirring up conflicts.”
2. verb
To provoke or cause trouble for someone, often in a deliberate or manipulative manner.
“He antagonized his coworker by spreading false rumors about her project.”