That man behaves like an overgrown child.

那男子一举一动像个大男孩。

youdao

His son, an overgrown child still living at home at the age of 35.

他的儿子已经是个超大的孩子，35岁了还住在家里。

youdao

The size of small child, it has a soft torso with a bald head, a doll-like face, and stumps in place of limbs. It looks like an overgrown fetus.

Telenoid有点卡通的设，和小孩子一般大小，拥有柔软的躯体，光秃秃的脑袋，娃娃一般的脸蛋，四肢残缺，像一个过度生长的胎儿。

youdao

Yet some still cling to protectionist tariffs like an overgrown child to a security blanket.

CNN: Full Speed Ahead

For an overgrown child of the Italian state, which has often been forced to put politics before profitability, Finmeccanica, Alenia's parent company, is proving extremely agile at one thing: flirtation.

ECONOMIST: The defence industry

Curly was just an overgrown man-child simpleton.

FORBES: AMC Podcast Offers a Peek Inside the Brain of Breaking Bad