cocoon

The silkworm spins a soft white cocoon before it transforms into a moth.

(Chinese) 蚕在变成蛾之前会吐丝织成一个柔软的白色茧。

She felt safe and warm inside her thick down blanket, like a caterpillar in a cocoon.

(Chinese) 在厚厚的羽绒毯里，她感到既安全又温暖，就像茧里的毛虫一样。