piranha

中文： 食人鲳、水虎鱼、比拉鱼、食人鱼

1. Any of certain freshwater fish of the subfamily Serrasalminae, native to South America; they are characterized by razor-sharp teeth and a reputation of being ferocious predators (despite most species being omnivorous).
2. Someone, especially a critic, who appears to be part of a swarm and attacks someone when they are vulnerable, as if in a feeding frenzy. (figuratively)

复数 piranhas