The Pumpkinator shard is a hero shard, but if you equip it into a weapon it will be triggered from all your defenses too. This can lead to millions of damage on an explosion of a pumpkin, because it scales of the hero, the tower kinda get another layer of aoe damage from the hero. It's a fun mechanic but an abusiv bug.
Steps to reproduce:
Pumpkinator only works for Hero attacks.