__ Pets; Mechanical Zooming Pet Hamsters
Puzzle 17 of Countdown to 2020 Piece of Cake Pack
Question is: __ Pets; Mechanical Zooming Pet Hamsters
and the answer is: ZHUZHU
Word Meaning:
ZHU — (historical) An ancient Chinese unit of weight, notionally equivalent to 100 millet seeds or 1/24 of the liang/tael/Chinese ounce, chiefly used in denominating small coins in ancient and early imperial China.
Definitions from Wiktionary.