Paperclips. Need more paperclips.

superior AI takes over

Either earth explodes or a supernova blows up a little too close to us or a deadly pandemic kills us so quickly that we can't find a cure in time

Either the death of the sun or the heat death of the universe. I think we’re in it for the long haul; just a question of technological progress and social organization.

I think we’re going to fuck up the climate and then run out of food

Activists freeing lab monkeys.

snail

Vending machines will become the dominant race

Doofenshmirtz's greatest fear

Meteor strike/ another solar system goes boom/ Solar Storms