A really impressive piece that caught my attention immediately. Your digital art style is amazing, it looks like watercolor and oil paint splatters, over all a very nice effect.
Three best aspects:
1. Again, the splattered, messy style; it makes everything look alive.
2. The color theme; sort of a swampy green is very Medusa.
3. The random twists and turns of the snake hair is perfectly wild and chaotic.
Two aspects which I think could be improved:
1. The green part of her eyes are a bit dull - maybe make the shadows and highlights more visible, different textures, etc...
2. The snake nearest to her left eye has a very bright yellow color in its own eye - the snake head nearest to her left eye should also have this color.

I hope this was helpful.
*nfaas.