狗嘴裏吐不出象牙

1. • lit. no ivory comes from the mouth of a dog (idiom)
2. • fig. one does not expect fine words from a scoundrel

Character by character

• 狗(gǒu)dog
• 嘴(zuǐ)mouth
• 裏(li)
• 吐(tǔ)spit
• 不(bù)no
• 出(chū)go out
• 象(xiàng)elephant
• 牙(yá)tooth