the joker in the pack

someone or something that could change a situation in a way that you do not expect The independent candidate is the joker in the pack in this election.

Common Names:

Name	Pronounced	Usage
Hayley	HAY-lee	English (Modern)
Liorit	-	Hebrew
Lavrentios	-	Greek
Atanasija	-	Serbian, Macedonian
Kasparas	-	Lithuanian
Roosevelt	ROZ-ə-velt	English