A saltwater fish famous for its “friendly” personality, the Longhorn Cowfish (Lactoria cornuta), also known as the Yellow Boxfish or Horned Boxfish, is a sought-after choice for experienced aquarists. The omnivorous Longhorn Cowfish is known to pick at tubeworms and other reef residents, so use caution if placing this fish in a reef system. This fish is also poisonous, and can release toxins from its skin if threatened!