Plague of Frogs is the first cycle of B.P.R.D. stories. Following the release of King of Fear #5 it was announced that future B.P.R.D. stories would come under the Hell on Earth title. All past B.P.R.D. titles come under the Plague of Frogs title, making it the first story cycle. A number of B.P.R.D. stories published after this time were not collected in the Plague of Frogs omnibus editions. These stories were set prior to the Plague of Frogs story cycle and were collected in the trade paperback B.P.R.D.: Being Human.