Lungless Frog

An animal that can breathe through its skin and not through its lungs might sound a little alien-like, but strangely enough, this animal lives on Earth and is known as Barbourula kalimantanensis, the frog without lungs.

The first recorded species of frog that breathes without lungs was found in a clear, cold-water stream on the island of Borneo in Indonesia. It gets all of its oxygen through its skin.

"Nobody knew about the lunglessness before we accidentally discovered it doing routine dissections," study lead author David Bickford, a biologist at the National University of Singapore, said in an email.

Poison Dart Frog

Tiny poison dart frogs may only be one inch (2.5 centimeters) long, but they pack a powerful punch—of poison. Weighing less than an ounce (28 grams), these frogs are considered one of Earth's most toxic, or poisonous, species. For example, the golden poison dart frog has enough poison to kill 20,000 mice.

With a range of bright colors—yellows, oranges, reds, greens, blues—they aren't just big show-offs, either. Those colorful designs tell potential predators, "I'm toxic. Don't eat me."

Scientists think that poison dart frogs get their toxicity from some of the insects they eat. The insects feed on plants that have toxins, which then pass to the frogs when they eat the insects. Poison dart