noun
mud pie
A lump of mud shaped like a manjū bun, often made by children playing in the dirt.
子供たちは庭で泥饅頭を作って遊んでいた。
The children were playing in the garden, making mud pies.
泥団子 is a mud ball, often polished to a shine, while 泥饅頭 specifically refers to a mud pie shaped like a manjū bun.
Compound of 泥 (doro, 'mud') and 饅頭 (manjū, 'steamed bun'), referring to a mud pie shaped like a manjū.