
to be passionate about something at the beginning but soon lose their interest 虎頭蛇尾
Sitting on a hill watching tigersfight 坐山觀虎斗 (It means someone takes a side in a fight until one partyoverwhelms their enemy. )
A goat in tiger's skin 羊質虎皮 (It means someone who appears strong on the outside but is timid on the inside。)