They Are Among Us! was a special event that aired on UltraToons Network from May 2, 2014 through May 30, 2014. The special featured the monster and alien-themed episodes of shows like Pet Alien, The Life and Times of Juniper Lee, Ben 10 and others, as well as the reruns of the cartoon shows. Also, this special was a similar to Cartoon Network's Invaded special from May 2006, Nicktoons Network's 3HM block from 2005 to 2007 and Cartoon Network Italy's Sono Tra Noi special from 2006.
It follows that the monster and alien invasion in the city (from the network's promotional rebrand), when all the characters from the shows were scary and terrified (seen on bumpers and promos).