Why did Frieza need the second transformation? When Frieza transformed the first time, he said his fighting power in that transformed state was one million. But when Piccolo comes to fight Frieza, after a little while, Frieza undergoes his second transformation. What was the reason?


Was Frieza bluffing when he said his fighting power in that transformed state was one million?
Did Piccolo become really very strong after his fusion with Neil that his fighting power reached to a level comparable to Frieza?
Was Frieza afraid of losing, as a result of which he thought transforming would be a good option?




And then, after a few episodes, Frieza undergoes another transformation after seeing the amount of power Gohan had. So did Frieza start to panic out?
Because Piccolo's power level was higher than his, as stated in the Dragon Ball Wikia -


  Thanks to his fusion with Nail, his power is slightly higher than that
  of Frieza's.Through much of the battle, Piccolo has the upper hand, but Frieza transforms again into his third stage, earning yet another power increase.