Niue, a sovereign state in free association with New Zealand, uses two official legal tender currencies. The New Zealand Dollar is the circulation currency for daily transactions, while the government also authorises legal tender coins in the Niue Dollar currency for collector's purposes.
A number of mints issue a large variety of commemorative, bullion and collector coins under the authority of Niue. These coins are dedicated to historical or general popular culture themes not related to Niue itself. Many of them are in standard bullion sizes, based on the troy ounce - such as the half ounce of silver format (abbreviated as 1/2 oz Ag, where "Ag" comes from the Latin word for silver, Argentum).
This silver coin, called by the mint The Water Tiger, is dedicated to the Chinese Lunar Year of the Tiger 2022.
The mint says about it:
The Water Tiger coin consists of more than 2,800 tiny mirrors that are reminiscent of water droplets. At the heart of the reverse, there is an image of a majestic tiger head made of those mirrors. When the coin is turned, each tiny silver mirror dot reflects the light - just like the surface of the water twinkles on a sunny day. | 
Search for Niue: Silver Half Ounce 2022 Year of the Tiger on eBay 