Regal Horned Lizard - Phrynosoma solare | ©Jason Penney (Tohono O’odham Indian Reservation, southwest Arizona, US)
Phyrnosoma solare (Phrynosomatidae) are among the larger species of Horned Lizard. Their Latin name is derived from the meaning "rays of the sun" by referring to four large occipital horns at the base of the head continuous with six temporal horns, form a large crown of ten sharp, pointed horns along the base of the head.
American group of Regal Horned lizards have evolved an exceptionally bizarre defense against predators: when under threat they can restrict blood flow from the head until mounting pressure ruptures small blood vessels in and around the eyes, resulting in a spurt of blood that may leap a meter (3 1/2 feet) or more [source].