Faction doesn't appear to work

[SlimeCrusher]

I made a custom faction and made a custom pawn i made use it, but i can't see the faction on the debug menu (Using "raid from"), i don't know what's wrong as there are no errors on the console...
Also, the pawn itself works, but it behaves like a squirrel, completely ignoring my colonists when it should attack them 

Here's the code from BaseFactionDefs:

<?xml version="1.0" encoding="utf-8" ?>
<FactionDefs>




  <!-- Special non-humanoid factions -->

  <FactionDef>
    <defName>Xen</defName>
    <label>xen</label>
    <description>bla</description>
    <pawnsPlural>xenians</pawnsPlural>
    <requiredCountAtGameStart>1</requiredCountAtGameStart>
    <fixedName>xen</fixedName>
    <raidCommonality>67</raidCommonality>
    <humanoidFaction>false</humanoidFaction>
    <hidden>true</hidden>
    <canFlee>false</canFlee>
    <techLevel>Ultra</techLevel>
    <startingGoodwill>
      <min>-100</min>
      <max>-100</max>
    </startingGoodwill>
    <naturalColonyGoodwill>
      <min>-100</min>
      <max>-100</max>
    </naturalColonyGoodwill>
    <spawnGroups>
      <li>
        <selectionWeight>100</selectionWeight>
        <kinds>
          <li>Headcrab</li>
        </kinds>
      </li>
    </spawnGroups>
    <homeIconPath>World/FactionHomes/DefaultHome</homeIconPath>
    <homeIconColor>(150,150,150)</homeIconColor>
  </FactionDef>



</FactionDefs>

What did i do wrong? I literally just copy-pasted the code from "a mechanoid hive" faction and changed it a bit...

[Rikiki]

Have you created a new world?
New faction need a fresh world.

[SlimeCrusher]

... Oh... I knew i was supposed to make a new thing, i thought it was a colony and not a world lol
Thanks about that 

But im having a problem, when i force a raid from "xen", i get an error on the console and the pawn doesn't move, the error is "Xen_Headcrab7473 threw exception while determining job: System.NullReferenceException: Object reference not set to an instance of an object". The pawn worked before but now it doesn't...

[Rikiki]

Please post the pawn XML def so we can look at it.
Your full project in .zip would be best.

[SlimeCrusher]

Edit: Nevermind just fixed the console problem (I changed the thinktree from "Mechanoid" to "StandardHerbivore", that seemed to work), but im back on where i started:
The pawns don't attack humans...

I even tried putting ALOT of my pawns, and then a centipede, the centipede then started shooting at my headcrabs, but only one went and tried to attack him. Another strange thing, my colonists will try to kill the headcrabs if i give them a weapon or make them walk in the way of the headcrab...
Any idea on how to make a pawn attack? :/

[Rikiki]

Have you tried to put <thinkTree>Mechanoid</thinkTree>?
It is normal that peaceful animals don't attack (for now...).

[SlimeCrusher]

Yea, did that, you know, the cause of the console errors problem WAS putting "<thinkTree>Mechanoid</thinkTree>" 
It may be because im not using the baseMechanoid thing and instead im using baseAnimal, that was so my pawn wasn't made out of metal lol

Edit: Do i simply give up? I will try adding the baseMechanoid thing maybe that works, but it'll be made out of metal... I remember back in alpha 3 where you just put the default faction to "Raider" and the pawn was automatically hostile :/