n.顽皮的人；爱开玩笑的人
The prankster likes pranking, and he always made prank calls to others, and telling that their kins are in danger. 那个顽皮的人喜欢搞恶作剧，他老是给别人打恶作剧电话，然后告诉别人他们的亲戚有危险。
I thought it was an emergency, but I found out when I arrived it was only a prankster crying wolf. 我本以为是件突发事件，可当我赶到的时候却发现那只是个爱开玩笑的人的谎言而已。
