Meaning:
“毒” means “poisonous,” and “奶” means “milk.” Originally used by gamers and commentators of games, this term means “to jinx by praising.” Among Chinese players of “World of Warcrafts,” the character “奶” refers to “healers” who help their teammates to recover from injuries. Therefore, “poisonous milk” refers to those who have adverse effects on the performance of their teammates. As a more general term, this has been used in the discussion of sports games or even the performance of stocks.
Example:
A: 这届奥运会你看的比赛多吗？
Zhèjiè àoyùnhuì nǐ kàn de bǐsài duō ma？
Did you watch a lot of the Tokyo Olympics?
B: 不是特别多，我感觉自己是毒奶，所以只有中国队稳赢的比赛我才敢看。
Búshì tèbié duō, wǒ gǎnjué zìjǐ shì dúnǎi, suǒyǐ zhīyǒu zhōngguóduì wěnyíng de bǐsài wǒ cái gǎn kàn。
Not much. I felt like I was kind of a jinx, and only dared to root for our athletes in competitions they dominated.
A: 没想到你还这么迷信。
Méi xiǎngdào nǐ hái zhème míxìn。
I didn’t know you were so superstitious.