pesky
Usually, what drives people to get disgruntled at work leading to job searching are one of the following things - too much work, a boss who you don’t see eye-to-eye with or a client who drives you crazy.
However, at this point for me, there’s only one thing that makes me not want to come to work in the morning - a pesky co-worker who is the same level as me, but is like a thorn in my side. Kind of weird huh?