Largest eye-to-body ratio
Vampyroteuthis infernalis

The vampire squid (Vampyroteuthis infernalis) has the largest eye-to-body ratio of any animal in the world. Its body reaches a maximum length of 28 cm (11 in) while its eyes can have a diameter of 2.5 cm (0.9 in). First discovered in 1903 by Carl Chun, the vampire squid has been found to reside in tropical waters at depths of over 600 m (1,970 ft).

Its body is covered in light-producing organs called photophores which it uses to distract predators. It has a gelatinous body which can be black, red, purple or brown depending on its location. Vampyroteuthis infernalis (translates as 'vampire squid from hell') is the only member of the Order Vampyromorphida and is completely harmless.