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
Zornitsa	-	Bulgarian
Elihu	i-LIE-hyoo (English), ee-LIE-hyoo (English)	Biblical, Biblical Hebrew, English (Archaic)
Ji-Eun	jee-uwn	Korean
Cenhelm	-	Anglo-Saxon
Nora	NAWR-ə (English), NO-rah (German)	Irish, English, Swedish, Norwegian, Danish, German, Dutch, Italian
Gus (2)	GUS	Greek