I think you're focusing too much on filling the body with a solid color. You will probably benefit from using a single line stroke for the body, just as you have done for the head. Be mindful of your curves as well. It looks like you're losing symmetry in some places.
The thickness of your strokes is right on the bottom samples, but I would lose the beard. It looks more like a bearded snake than it does a lion and snake combined. Consider using a lion's head, but replacing the tongue with a snake tongue. Or perhaps replacing a lion's tongue with a snake entirely. Just my opinion, but I don't think creating an animal hybrid works for this.
Keep it up. I appreciate the fact that you're sketching your own ideas and executing them rather than regurgitating some other designs that you find online.
Wow, thanks for the feedback, appreciated a lot. I really had trouble with the body almost took 2 hours to adjust it, obviously there was a problem it shouldn't take that long. It was easy with pen and paper with shadings but was hard to apply with single color, tried to keep it consistent with the relevant FPL logo. About the symmetry I tried to follow a tail like shape that's why it's out of symmetry. It made it more illustrative rather than a logo but I don't know call it matter of choice? :)
Beard was the quick solution to get rid of the body (which I failed to draw). As the previous drawing an open mouth made it look aggressive, I don't know If I were able to draw a hybrid animal really. But I should definitely try it.