So we're looking at what we are going to do in the future for the zombie 'looks'. Theres some choices listed above but feel free to name your own here.
1. You create your zombie by picking a predefined one and change its appearance using a menu similar to Skyrim / Fallout 4. You will always spawn as this zombie. (No crazy options will be available, its got to fit the rest of the theme.)
2. You pick a predefined zombie that changes based on your zombie skilltree choices. (like picking more hp makes him/her become fatter.) Similar like how in GTA:SA you could train at the gym and make CJ ripped. (Or fat if you kept eating food)
3. We make a nice amount of zombies, and on spawn you just get assigned a random one. (Just like ZombieX in CoD5.)
4. Name your own idea on how to tackle this. (perhaps mix 2 and 3 and pick your own which isnt affected by skilltree?)
Keep in mind that option 1 takes a huge amount of time as we don't know yet on how to do it. Whilst 3 is the easiest one to implement. (And 2 is inbetween)