BabyEntitySpawnEvent is fired just before a baby entity is about to be spawned. 
 Parents will have disengaged their relationship. 
@Cancelable 
 It is possible to change the child completely by using 
setChild(EntityAgeable) 
 This event is fired from 
EntityAIMate.spawnBaby() and 
EntityAIVillagerMate.giveBirth() 
 
 parentA contains the initiating parent entity.
 
parentB contains the secondary parent entity.
 
causedByPlayer contains the player responsible for the breading (if applicable).
 
child contains the child that will be spawned.
 
 This event is 
Cancelable.
 If this event is canceled, the child Entity is not added to the world, and the parents 
 will no longer attempt to mate.
 
 This event does not have a result. 
HasResult
 
 This event is fired on the 
MinecraftForge.EVENT_BUS.