User blog comment:DogzillaToon/What The Invasions?/@comment-2190739-20110803011434/@comment-3447485-20110805034044

@KacperTheHorse Or hacker made. But if the district is almost empty then sometimes an toon-summoned invasion can last 25 minutes. Also, I know of people who have collected every type of cog invasion. (Although I don't know why they would ever one at once.)