Which marine animal possesses a poisonous, barbed tail capable of fatal stings?

Stingray

Who was chosen to replace Judas Iscariot among the apostles? Who was Afghanistan's first president after the fall of the Taliban regime in 2001? Which friend had a recurring habit of proposing marriage casually when anxious? What medical device is used to hear heartbeats? What is the primary color of Persian saffron threads?