猴子(hóu zi) - monkey in Mandarin

猴子 (hóuzi) is the everyday word for a monkey. The measure word is 只: 一只猴子. As with 桌子 and 房子, the 子 here is an unstressed noun suffix rather than a word in its own right, so it is pronounced flat and light.

Monkeys sit deep in Chinese culture. 猴 is one of the twelve zodiac animals, and the Monkey King of Journey to the West is as familiar to a Chinese child as any character in English children's literature. Calling a restless child 小猴子 is affectionate, and 像只猴子 for someone who cannot keep still is a stock comparison.

The trap is reaching for it as an insult, which is where English speakers get into trouble across languages generally. In Mandarin the animal comparisons that sting are different ones, and 猴子 pointed at an adult reads as mocking their fidgeting or their looks rather than anything worse. Keep it for the animal and for children, and you will never misfire.