Amphibians are vertebrates that live in both water and land. This group of cold-blooded animals undergoes complete metamorphosis, usually the eggs are laid in water or moist areas, by external fertilization. Its characteristics are thin, smooth, hairy and porous, the skin contains mucous glands and poison glands, the feet have membranes. Breathing can be done separately or in combination with the lungs, skin and gills. Has a closed blood circulation, where the heart consists of 3 chambers, namely 2 atria and 1 ventricle.