25 Dollars - Elizabeth II Year of the Rat

The Year of the Rat carries particular weight in the 2020 lunar cycle — it opened the twelve-year zodiac sequence and coincided, with grim timing, with the earliest weeks of the COVID-19 outbreak first identified in Wuhan in late 2019. Cook Islands has issued lunar-themed silver kilo and half-kilo pieces through the New Zealand–administered territory's licensing arrangements for decades, with the actual striking contracted to external mints rather than any facility on the islands themselves, which have no mint infrastructure.

At 155.5 g, this sits in the five-troy-ounce category that became a collector staple in the 2010s as spot silver remained low enough to make large-format issues commercially viable.