You know what makes drawing perspective really easy? Here's my secret.
Spoiler
Use the perspective buttons on Gimp XD
haha. But seriously, I think this was good practice. I think you could've even gone a bit more with the perspecitve and made the tail look tiny-er and the head even bigger. Also, by putting some kind of background (maybe stars or clouds or something) you can make those look tiny in the back and bigger toward the bottom, or front of the picture. Those kinds of things would just emphasize the whole focus of this exercise.
I like the dragon, too. It reminds me of a komodo dragon, or maybe that's just because I wrote a 15 page report on komodo dragons a few weeks ago... idk.
Keep drawing!
The bad news is we don't have any control. The good news is we can't make any mistakes. -Chuck Palahniuk