螳螂捕蝉，黄雀在后

tángláng bǔ chán, huángquè zài hòu

[covet gains ahead without being aware of danger behind as the mantis stalk the cicade, unaware of the oriole behind] 螳螂一心一意要吃蝉, 而背后的黄雀却正盯着它。 比喻只看到前面的利益, 而不顾身后的危害