Bliking

Bliking (ブリキング) is the boss of the second Wily Tower Stage. It can only be damaged when its wings are fully extended. But it shoots some mines, can send electrical shots, shoot missiles from its tail, and even try to ram at the player. The best weapon to use against it is Astro Crush.

Trivia
Coincidentally, one of the ships from One Piece is called Bliking.

The boss itself bears a heavy resemblance to the robots seen in the Hayao Miyazaki film Castle in the Sky.