Eep! This tiny thing is a female Blue Duiker calf — born December 8 at Fresno Chaffee Zoo. According to Zooborns:

The calf weighs 1lb and stands 5 inches tall at her withers. Duikers are among the smallest of Antelope species and generally weigh only 20 to 26 pounds when fully grown. Duikers are found throughout sub-Saharan Africa in wetlands, rainforests and timber-heavy regions. Although they browse on grass, leaves, shrubs and trees, Duikers are classified as frugivores because the main component of their diet is fruit.

More pictures right here!