Photo by Julie Larsen Maher/WCS

This little baby one-horned rhinoceros (Rhinoceros unicornis!), or Indian rhino calf, was born at the Bronx Zoo in April and just made its debut. The female weighed 120 lbs at birth, and is expected gain about 3,500 lbs more, at least. Its skin resembles armor plating, but the Wildlife Conservation Society says "it is more sensitive than it appears. Rhinos frequently spend time in mud wallows to cool their skin and regulate their body temperature. The mud works to protect their skin from the sun."

Check out the little gal below, rolling around in the mud and looking like the oldest newborn we've ever seen: