<Operation Class="PatchOperationFindMod">
    <mods>
        <li>Alpha Animals</li>
    </mods>
    <match Class="PatchOperationReplace">
      <xpath>/Defs/ThingDef[defName = "AA_Darkbeast"]/race/leatherDef</xpath>
      <value>
         <leatherDef>Leather_Chitin</leatherDef>
      </value>
    </match>
</Operation>

<Operation Class="PatchOperationFindMod">
    <mods>
        <li>Alpha Animals</li>
    </mods>
    <match Class="PatchOperationReplace">
      <xpath>/Defs/ThingDef[defName = "AA_SandProwler"]/race/leatherDef</xpath>
      <value>
         <leatherDef>Leather_Chitin</leatherDef>
      </value>
    </match>
</Operation>

<Operation Class="PatchOperationFindMod">
    <mods>
        <li>Alpha Animals</li>
    </mods>
    <match Class="PatchOperationReplace">
      <xpath>/Defs/ThingDef[defName = "AA_Thunderbeast"]/race/leatherDef</xpath>
      <value>
         <leatherDef>Leather_Chitin</leatherDef>
      </value>
    </match>
</Operation>