菇凉百毒不侵
[gū liáng băi dú bù qīn]
A playful phrase where '菇凉' (gū liang) can mean either mushrooms or a way of addressing a girl informally. '百毒不侵' (bǎidú bùqīn) refers to being impervious to harm, literally 'impervious to a hundred poisons'. So it can be interpreted as 'the girl is tough and unbreakable' or 'this mushroom is resistant to everything'.