Longhorn Cowfish (Lactoria cornuta)
A variety of boxfish from the family Ostraciidae, recognizable by its long horns that protrude from the front of its head, rather like those of a cow or bull. They are a resident of the Indo-Pacific region and can grow up to 20 inches long. Whilst badly suited to the home aquarium, the cowfish is becoming increasingly popular as a pet.
If severely stressed, this species may be able to exude deadly toxin, ostracitoxin, an ichthyotoxic, hemolytic, heat-stable, non-dialyzable, non-protein poison in the mucous secretions of their skin. It is apparently unique among known fish poisons; it is toxic to boxfish and resembles red tide and sea cucumber toxins in general properties.