Wūrǎn

Subway stations here are running this ad campaign against pollution.  In the corner of this one, it says 污染猛于虎 (wūrǎn měng yú hǔ or “pollution is fiercer than a tiger.”)
 This one says 污染毒于蛇 (wūrǎn dú yú shé or “pollution is more venomous than a snake.”)
 And this one says 污染毒于蛇 (wūrǎn qiáng yú xióng or “pollution is stronger than a bear.”)