I like the sprites and descriptions, but the adult's tail bothers me just a bit.
It looks thin near the base, it gets thicker to where the gold bands are before becoming narrow very quickly.
If that could be smoothed out, I think it would look better.
The blue shows where it got thicker, the red is the sudden thickness changing area, if that makes sense.
Where the tail joins the body seems a little off as well, I just can't place why.