How to make the boss's health go down

I need to be able to shoot my bow at the boss, and it will take away it’s health. No idea how though.

Game: http://flowlab.io/game/view/112068

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Okay, now I understand. thanks!

Hey john, if you look at my game, when you get to the boss stage it doesn’t show the health bar. Am I doing something wrong?

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mmmm k ill try that

Is there any way that I can make the bar appear only when I’m in the boss room?

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