What animal is Gemini?

Excuse me, could you please clarify something for me? I've come across the phrase "Gemini" and I'm wondering if it refers to a specific animal. Is there a direct correlation between the zodiac sign of Gemini and any particular animal? If so, could you elaborate on what that animal might be and why it's associated with Gemini? I'm genuinely curious about this connection and how it might tie into astrology or cultural beliefs.