チームジャンパー

noun

team jumper

A person who frequently switches teams or groups, often in sports, esports, or workplace contexts. Carries a slightly negative nuance of disloyalty or opportunism.

• 彼かれはまたチームを移うつったらしい。本ほん当とうにチームジャンパーだね。

  He seems to have switched teams again. He's a real team jumper.