狗改不了吃屎

1. • lit. a dog can't stop himself from eating shit (idiom)
2. • fig. bad habits are hard to change

Character by character

• 狗(gǒu)dog
• 改(gǎi)change
• 不(bù)no
• 了(liǎo)finish
• 吃(chī)eat
• 屎(shǐ)feces