A Freezing Rod
Talk to Kula in the Great Hyrule Forest. Kula is near Chio and Peeks and will ask you to bring an Ice Rod, a weapon carried by Ice Wizzrobes. Note that a Blizzard Rod also will suffice.
If you have a photo of the Ice Wizzrobe in your Hyrule Compedium, you can set it as your sensor. Ice Wizzrobe can also be found aroud the Lanayru area and one in particular camps out right next to the Lanayru Tower. Once you can get yourself an Ice or Blizzard Rod drop, bring it back to Kula.
Kula will give you a silver Rupee worth 100 Rupees as a gift of thanks. After this, you are free to drop the Ice Rod. You don't have to keep it anymore.