Preety good, but if you were fighting a dragon, would you really be standing in the stance? Put him facing the dragon.. The dragon doesn't look very fierce at the moment, give him some horns or some kind of skinny thing hanging from its head or a mane or something.. The fire is really good, you should start shading now though, just start with block shading then start to expand your own unique shading style, just pick a darker colour and draw where the shading would be (in the sig you just posted, it would be on the left side of the picture because the fire would be the light source. Good job.