Nice to see a unique and interesting character design.
Here's a few little changes you could consider. I did this ultra quick so it's a bit sloppy:

- Gave him more of a forehead, his face looked too long to me. All I did was drag the eyes and eyebrows down a bit.
- Changed skin from earthworm pink to a more tanned look. Used only 3 shades because I'm short on time
.
- Adjusted lighting from side on to top down.
Hopefully this might help you out a bit
.
Here's a few little changes you could consider. I did this ultra quick so it's a bit sloppy:
- Gave him more of a forehead, his face looked too long to me. All I did was drag the eyes and eyebrows down a bit.
- Changed skin from earthworm pink to a more tanned look. Used only 3 shades because I'm short on time

- Adjusted lighting from side on to top down.
Hopefully this might help you out a bit
