The Freeze has the ability to freeze anything or anyone, create weapons of ice, and drop the temperature of an area to the freezing point and possibly lower. It is very resourceful, using glaciers and pillar's of ice to attack from behind. The main body of Freeze is a koi fish made of ice, like the one depicted on its card.
The Freeze first appears in Episode 33 where it turn the temperature of the skating rink Sakura's class was taking a fieldtrip to freezing. As well as the freezing temperature, all of Sakura's classmates (except for Syaoran, Kaho Mizuki, and herself) were frozen in magical ice. Ms. Mizuki hides, later implying she wanted Sakura and Syaoran to take care of it themselves though the real reason is left unsaid, leaving the two to fight Freeze. It swims through the ice like it was water, but is quickly overcome by Syaoran and Sakura sealed it. The Freeze originally goes to Syaoran, but in Episode 36 Sakura is shown having and controlling it. This may have been a mistake or Syaoran gave it to Sakura sometime offscreen between the two episodes.
The Freeze is transformed into a Sakura Card during Episode 60 when Eriol Hiiragizawa animated some penguins from Penguin Park. It was under Meiling's suggestion that she used Freeze to literaly freeze the penguins so she and Syaoran could destroy them.