(Actually I'm still working on the comic, and I haven't published it, but I like to show the design of the characters :p)
This is Doman's first drawing, I always thought his design was very simple, but I feel that it has just the right amount of details (the minimum possible)
This is the first drawing of Gas Devil, there are several changes compared to the final design, such as Jeff's hair or those goat legs, which would be changed in more current designs (also, Gas Devil was originally called "graybull"!)