8 Elusively Blue Animals: The Rarest Creatures of All

Blue Jay

Blue jay (Cyanocitta cristata) feathers should be black since it produces melanin. The bird's feathers seem blue because tiny air sacs scatter light. 

Blue Iguana

The newborn lizards are intricately patterned but barely blue, with just certain sections remaining blueish-gray. 

Glaucus atlanticus

The Portuguese man o' war (Physalia physalis), known for its deadly stingers, is eaten by the species as it floats upside down in the water. 

Mandarin Dragonet

The Pacific Ocean mandarin dragonet (Synchiropus splendidus) is one of two vertebrates whose blue hue comes from cellular pigment rather than structural coloration.

Blue Poison Dart Frog

The frog's skin cells generate aposematism, which turns it blue to alert predators that it's deadly.

Blue Morpho

Morpho butterflies, known as blue morphos, have gorgeous blue wings. 

Sinai Agama

The Sinai agama is one of the rare blue reptiles, as males turn vivid blue during breeding season to attract females.

Linckia laevigata

Indo-Pacific tropical waters are home to Linckia laevigata sea stars. Individual sea stars vary in hue from pale blue to dark blue.