This annoying coworker is especially frustrating because he/she will often feign friendship and then stab you in the back five minutes later.
Did you discuss a great idea with a coworker only to see that person steal it and use it as their own? Are you missing meetings because your coworker leading a project keeps “forgetting” to email you the invites? If so, you’re probably dealing with The Bully’s sneaky and conniving cousin – The Underminer.
The most important thing to remember here is that The Underminer sees you as a threat and is genuinely scared of you. Try to keep that in mind and use it to your advantage when dealing with him/her.