First of all thanks to Coby for pointing out the modability & for answering all my questions!
With some playing around I now can present my first fully working enemy type:
The Golden Goblin
This little guy will charge at you in cardinal directions only, but with much greater speeds and force than its common cousins. It's higher resistance to punishment and has a tendency to appear together with normal goblins or other hazards.
The picture shows the rogue facing off against a golden gobling in a fireball grid.
I'll propably do a few more enemies until the alpha is out, so if anyone wants to try fighting against these, let me know.