Whenever someone close to Nack dies or looks to be dying, he can't help but scream his Big "NO!" in terror.
In the adaption of Conkers Bad Fur Day, it's not just Berri that dies in the alternate world, but also the AU bounty hunter friends (AU Nic as well) AU Nack of that universe and Psycho had cherished being killed within the alternate world.
Batula's death in the AU world could count as well. It even made the author writing cry.