挂羊头卖狗肉 (guà yáng tóu mài gǒu ròu)

挂羊头卖狗肉

(guà yáng tóu mài gǒu ròu)
English Translation:“Hanging the sheep’s head and selling dog meat.”

Meaning:
If you’re passing one thing off as another, you’re deceiving people. This is used to describe dishonesty or misleading actions.

Example:
这个商店挂羊头卖狗肉，卖的东西和广告完全不符。
(This shop is “hanging the sheep’s head and selling dog meat”; the products are completely different from what was advertised.)

Source: Hello Mandarin