This event is fired whenever a Living Entity creature is killed in order to calculate the looting level. The value can be increased or decreased or left as-is. The value may have already been modified by other events, but the original value is not included.

You will need to cast the event in the function header as this class:
crafttweaker.event.LootingLevelEvent
You can, of course, also import the class before and use that name then.

LootingLevel Events implement the following interfaces and are able to call all of their methods/getters/setters as well:

• ILivingEvent

The following information can be retrieved/set during the event:

ZenGetter	ZenSetter	Type
ZenGetter lootingLevel	ZenSetter lootingLevel	Type int
ZenGetter damageSource	ZenSetter ​	Type IDamageSource