A new species of amphibian that's Kermit the Frog's doppelganger has been discovered in the Costa Rican rainforest.

The lime-green frog, coined hyalinobatrachium dianea after the lead study author's mother Janet Diane Kubicki, is the 14th type of glass frog in the country, the Costa Rican Amphibian Research Center says.

The Muppets-like frog is unique as its belly is translucent, offering a view of the animal's internal organs.