This frog holds the record as the world's smallest vertebrate, measuring just 7.7 millimeters (0.30 inches) in length. It was discovered in Papua New Guinea.
The smallest bird, this hummingbird measures about 5.5 centimeters (2.2 inches) in length and weighs approximately 1.6-2 grams (0.056-0.071 ounces).
This tiny monkey, native to the Amazon Basin, measures about 13-15 centimeters (5.1-5.9 inches) in body length, with a tail of about 15-20 centimeters (5.9-7.9 inches), and weighs around 100 grams (3.5 ounces).
One of the smallest primates, this tarsier measures about 85-160 millimeters (3.3-6.3 inches) in body length and weighs between 80-160 grams (2.8-5.6 ounces).
The smallest rabbit species, pygmy rabbits weigh around 375-500 grams (13-17.6 ounces) and measure about 23.5-29.5 centimeters (9.3-11.6 inches) in length.
These tiny seahorses measure about 2 centimeters (0.8 inches) in length and are masters of camouflage, blending in with the coral reefs they inhabit.
This small tortoise, found in South Africa, measures about 6-8 centimeters (2.4-3.1 inches) in length and weighs 95-165 grams (3.4-5.8 ounces).
The smallest known fish, and vertebrate, Paedocypris measures just 7.9 millimeters (0.31 inches) in length and is found in the swamps of Southeast Asia.