HYDRA

Hydra heads will appear and start changing color.
Click on the heads when they are green to cut them off.
Once a head has changed color, you will have to get it back to blue by clicking to change it back to its previous color before you can cut it off.
Once a head reaches red, it will spew fire and end the game.
Oh and... once you cut off a Hydra's head, another two will grow in its place. Good Luck!