Flamer
What does flamer mean?
A person who angers other Internet users
Example
"That flamer was too much for me.
Yeah I had to leave the forum when he started talking about Trump."
Yeah I had to leave the forum when he started talking about Trump."

Flamers may make you punch a hole in your computer
Related Slang
Usage
Last Updated: August 17, 2016
A flamer is a person who enjoys flaming others, which involves purposely angering other Internet users. It commonly involves using profane insults to attack others when gaming, chatting, or posting in forums online.
A flamer is similar to a troll and griefer as it involves making people angry online. An expert flamer is one who targets other people who care about divisive issues such as religion and politics and makes statements to get a rise out of them.