The red drop of blood (left) was designated as an official emoji to symbolize menstruation, among other things, this year. The design at right, submitted in 2017, was not accepted.
Unicode; Plan International UK
The prehensile tailed skink from the highlands of New Papua New Guinea has green blood due to high concentrations of the green bile pigment biliverdin. The green bile pigment in the blood overwhelms the intense crimson color of red blood cells resulting in a striking lime-green coloration of the muscles, bones, and mucosal tissues.
Courtesy of Christopher C. Austin/LSU