Complex sentence: Seventy-five million years later, the Fog Mother returns to Earth with a new brood, while her three children perform the ritualistic prayer before going out to obtain the sacrifice for their siblings to feed on, so they may consume the human race.
Split into simpler sentences: Seventy-five million years later, the Fog Mother returns to Earth with a new brood. Her three children say a ritual prayer before going out to obtain a sacrifice for their siblings to feed on so they can consume the human race.