100 Francs Titanoboa

Titanoboa cerrejonensis was excavated from the Cerrejón coal mine in Colombia starting in 2009 — vertebrae so large that the original field team assumed they were dinosaur bones. Estimates place the snake at roughly 13 meters and 1,140 kilograms, making it the largest known snake in Earth's history, alive approximately 58 to 60 million years ago in a Paleocene rainforest considerably warmer than anything existing today.

The DRC has built a substantial revenue stream issuing fractional gold pieces tied to natural history subjects, targeting collector markets in Europe and Asia rather than any domestic circulation. At 0.5 grams of .9999 fine, the gold content is the point.