How To Beat The Dragon On Poptropica How Do You Beat Poptropica's Astro-Knights Island?

How do you beat Poptropica's Astro-Knights Island? - how to beat the dragon on poptropica

I know what to do, but now I try to kill the dragon on the inside of the volcano. I try to shoot the arrow of ice in your mouth while you, but breaks sharply to sleep, it will happen?