I did a edit check it out,
Notice how the light Is hitting the Zlerk from the top right,
"But most of the time when your drawing sprites you would want the
light to come from right above the sprites head"
The light in your picture looks like it's coming from below the Zlerk
because the bottom of it is lighter then the top if it.
One way to make shading less confusing is to shade any basic shapes first.
So you would draw a sphere at the size you want the Zlerk to be then
shade it before you put it's horn or face on.
Here is a well shaded sphere.
http://www.pixeljoint.com/pixelart/34555.htmwell it's sorta a sphere.
After your Zlerk's body looks round, add the other
body parts.
If you keep the first Zlerk body you could just make it a little bigger
to make the bodies for the other Zlerk life stages.
When your choosing colors you want to have high contrast,
"contrast is when it's easy to tell the colors apart."
And also make sure that the contrast is about even going
up your color ramp.
So each color is easy to see on the previous color.
