Сегодня – Pack Rat Day. Знаете, кто такой ‘pack rat’?
Это человек, который ничего не выбрасывает.. Плюшкин.

Примеры:

Her father is a real pack rat. He holds onto old magazines, newspapers, boxes, etc.

After living through tough times (war, the collapse of the Soviet Union, etc.), his grandmother became a real pack rat.