The Chinese zodiac animal paired with the Metal element in 2020 was the Rat.
2020 was the year of the Metal Rat, also called the White Rat in some traditional color-based descriptions. Its lunar year began on January 25, 2020, rather than on January 1. The year ended when Lunar New Year arrived in 2021.
The designation comes from combining a heavenly stem with an earthly branch. 2020 used the Geng stem, associated with Metal, and the Zi branch, associated with Rat. Together they form Geng-Zi, or Metal Rat, within the 60-year cycle.
This was the first Rat year since 2008, but the element changed: 2008 was an Earth Rat year. The animal repeats every twelve years, while the same animal-element pairing returns only after sixty years. These overlapping cycles explain why zodiac years can share an animal without sharing the same element.