Help With Custom Mob Procedures

I can't figure out how to make custom hostile mobs without using an AI base.

I'm trying to make an axe murderer. He's a biped with an axe, and spawns at night as a monster. 

I had made another mob that would kill creepers, but I messed with the code and he stopped working. I can't remember the code.

This is the AI tasks I have set up. I realize it doesn't make much sense but what would seem to make sense doesn't seem to work:

https://imgur.com/illIr1r