22:34:31 [SEVERE] Could not pass event CUSTOM_EVENT to ecoCreature
java.lang.NullPointerException
at se.crafted.chrisb.ecoCreature.managers.ecoRewardManager.registerCreatureDeath(ecoRewardManager.java:143)
at se.crafted.chrisb.ecoCreature.listeners.ecoDeathListener.onCreatureKilledByPlayer(ecoDeathListener.java:22)
at se.crafted.chrisb.ecoCreature.listeners.DeathEventsListener.onCustomEvent(DeathEventsListener.java:27)
at org.bukkit.plugin.java.JavaPluginLoader$97.execute(JavaPluginLoader.java:945)
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:58)
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:339)
at se.crafted.chrisb.ecoCreature.listeners.ecoEntityListener.onEntityDeath(ecoEntityListener.java:44)
at org.bukkit.plugin.java.JavaPluginLoader$65.execute(JavaPluginLoader.java:718)
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:58)
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:339)
at org.bukkit.craftbukkit.event.CraftEventFactory.callEntityDeathEvent(CraftEventFactory.java:305)
at net.minecraft.server.EntitySnowman.dropDeathLoot(EntitySnowman.java:89)
at net.minecraft.server.EntityLiving.die(EntityLiving.java:606)
at net.minecraft.server.EntityLiving.damageEntity(EntityLiving.java:502)
at net.minecraft.server.EntityHuman.f(EntityHuman.java:794)
at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:916)
at net.minecraft.server.Packet7UseEntity.a(SourceFile:33)
at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)
at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:93)
at org.getspout.spout.SpoutNetServerHandler.a(SpoutNetServerHandler.java:550)
at net.minecraft.server.NetworkListenThread.a(SourceFile:108)
at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:527)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:425)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:457)

Issue fixed in dev build:
http://ci.milkbowl.net/view/mung3r/job/ecoCreature/53/

Will be in the next release.