In real life
The Footballfish is a deep-sea anglerfish found in tropical and subtropical waters of the Atlantic, Indian, and Pacific Ocean. Like with other deep-sea anglerfish families, it 3,000 feet in the sea.Differences in appearance between males and females is extreme: the largest females may exceed lengths of 60 cm and are ball-shaped, whereas males do not exceed 4 cm as adults and are elongated and tapered at both ends. Both are a reddish brown to black in color.
It is suggested that female Footballfish are poor swimmers and largely lazy, lie-in-wait predators. They are primarily mesopelagic, living in open water, with very few caught below 1,000 m (3,280 ft). Females are carnivorous and feed upon other pelagic fish (such as lanternfishes and ridgeheads) and cephalopods, as well as shrimp and krill that are presumably attracted to within striking distance by the footballfish’ luminous lure.
Upon maturity, the males metamorphose into a parasitic form, which lacks both a lure and true teeth and is presumed not to feed. The parasitic males home in on the pheromones of the female and attach themselves to her body using their tooth-like hooks; the male’s tissues then begin to blend with the female’s, and the former’s organs begin to degenerate. The male thus becomes inseparable from the female, deriving nourishment directly from her blood.