Chinese

		knife	mouth	tofu; bean curd	heart; mind
simp. and trad. (刀子嘴豆腐心)		刀子	嘴	豆腐	心
Literally: “a mouth as sharp as a knife and heart as soft as tofu”.

Idiom

刀子嘴豆腐心

1. (slang) describes someone who has a sharp tongue but a soft heart; someone with more bark than bite

   我們都知道你是個刀子嘴豆腐心。 [MSC, trad.]

   我们都知道你是个刀子嘴豆腐心。 [MSC, simp.]

   Wǒmen dōu zhīdào nǐ shì ge dāozi zuǐ dòufu xīn. [Pinyin]

   We all know that even though you talk tough, you're a softy underneath it all.