The Giant Reptilian Bird is the hypothetical creation of foster care parents Mr. and Mrs. Weatherhead. Their rules of agnosticism state, "We cannot know for certain if God or Christ existed. They could. Then again there could be a giant reptilian bird in charge of everything. Can we be certain there isn't? No, so it's pointless to talk about."
- The Giant Reptilian Bird is similar to a now exctinct species called Gastornis, a flight-less bird that existed during the Cenozoic era.