<event>
  <action>
    <entry if_mob="zombie" action="1 + 2"/>
    <entry if_mob="skeleton" action="1 + 3"/>
  </action>
  <linked_action name="1" action="set" sub="hp" value="100" number_type="absolute"/>
  <linked_action name="2" action="set" sub="attack_power" value="8" number_type="absolute"/>
  <linked_action name="3" action="set" sub="attack_power" value="4" number_type="absolute"/>
</event>
<</code>>

OR

<event>
  <action>
    <entry if_mob="zombie" action="set" sub="hp" value="100"/>
  </action>
</event>