Original sentence: British big cats, also referred to as ABCs (Alien, or Anomalous, Big Cats), phantom cats and mystery cats, are Felidae not native to Britain which are reported to inhabit the British countryside
Edited sentence: British big cats, also referred to as ABCs (Alien, or Anomalous, Big Cats), phantom cats and mystery cats, are Felidae which may or may not be native to Britain which are reported to inhabit the British countryside