Lost ac plug, or "duckhead"

I have a Macbook Pro, which i bought a few weeks ago. Since then, I've only been using the power cord, the one with the three prongs, which plugs into the adapter, and I set aside the ac plug, which is called the duckhead. However, I seem to have lost the duckhead, so I was wondering if I could buy just the duckhead from Apple. I don't see any in the online store, but I chatted with Apple support, and the person said that she is pretty sure that Apple sells just the duckhead, which would be a lot cheaper than buying the whole adapter again. I'm going to call the store near me to see if they do sell it tomorrow, since it's past midnight right now.

Does anyone know if Apple does sell the duckhead by itself though? Or maybe if I could get it for free since I just bought the Macbook a few weeks ago...?

I was also wondering if the duckhead used for the Macbook charger is the same as the one on the iPad charger.