The rarity of Frozen Star is Mythical, and been equipped it takes a “Bundle” slot. At this moment the item is available for trade.
Frozen Star is a skin for Lich. The skin was added to the game on March 3, 2014, it was created by Vermilion Wlad.
Frozen Star is currently one of the most popular skins, but it is rarely seen in the game due to its high price.