Hidra -

Scientists named a genus of tiny freshwater organisms because of their remarkable regenerative abilities, reminiscent of the mythical beast. These creatures are simple, radially symmetric invertebrates related to jellyfish and corals.

The creature's most formidable trait was its : for every head cut off, two more would grow in its place. One of these heads was reportedly immortal. Defeating the beast was the second of the Twelve Labors of Heracles (Hercules). Heracles eventually succeeded by having his nephew, Iolaus, cauterize the stumps of the severed heads with fire to prevent them from growing back. 2. Biological Wonder: The "Immortal" Invertebrate Scientists named a genus of tiny freshwater organisms

In Greek mythology, the was a terrifying serpentine water monster that lived in the marshes of Lerna. It was the offspring of Typhon and Echidna, characterized by its multiple heads—the exact number varies by source, though nine is common. One of these heads was reportedly immortal