"It was maybe two or three meters from me and the eyes were bright red, reflecting my light. I was so frightened," Testa, a cave expert said.
In the course of his work, Testa has come across many weird and wonderful sightings -- but none as bizarre as this orange reptile with blazing red eyes.
Testa and his colleague crocodile expert Matt Shirley first visited the site in 2009 after an archeologist named Richard Oslisly spotted the crocodiles in the cave. They have visited the location in an isolated region of Gabon six more times
"First we confirmed that there were crocodiles in the cave and when we took one of them outside the cave, it was bright orange. That was amazing," Testa told CNN.
Little is known about the mystery crocodiles. However, recent research led by Shirley suggests that they may be evolving into a totally new species.
The species may be mutating as it has a different genetic haplotype to other African dwarf crocodiles living outside, which means that the reptile is adapting to life in the dark.
"The crocodile head shapes are much more archaic, brow ridges very marked, and the haplotype is a 1 haplotype found exclusively in the Abanda caves and nowhere else, including just outside," Oslisly told CNN.
Why are they orange?
Perhaps the most puzzling mystery is the color of the crocodiles.
They're not certain, but the scientists think it might be because of acidic bleaching.
"The crocodiles live in liquids -- that's guano (bat feces) -- and it's quite a harsh environment. There's a chemical attack on the skin and it bleaches the skin. But we don't have means to prove that," Testa told CNN.