A radio executive named George Richards bought the Spartans (Lions before they were called the Lions), moved to Detroit and decided to be called the Lions because the Lions are the kings of the jungle and George Richards wanted the Detroit Lions to be the king of the NFL.
The nickname "lions" is used to refer to the British and Irish Lions - A team made up of the best from the UK and Irish rugby union teams. This includes uncapped players who have missed national opportunities but are recognised for the Lions cap.
The sound of thunder is often called a thunderclap, a crash, a rumble, or a loud outburst. Thunder (a sound) is made by lightning (an electrostatic discharge). See the related Wikipedia and Online Dictionary links listed below: