The Oriental fire-bellied toad (Bombina orientalis) is one of the most colorful amphibians in Northeast Asia, yet it is tiny, only 4 to 5 cm long (1.5-2 in) and weighing about 30-50 g (1-2 oz). Its common name is misleading because it is not a true toad but a frog in the family Bombinatoridae. Found in Korea, northeastern China, and parts of Russia, it has a mossy-green back patterned with black, which helps it vanish against ponds and forest floors. But on its underside, it hides a surprise: a belly splashed with vivid red-orange and black spots.

Those belly colors are a classic case of aposematic coloration, warning signals in nature that say “I’m toxic, don’t eat me.” Predators often associate bright reds and oranges with danger and hesitate to attack. The fire-bellied toad does not display its warning constantly. Its green back keeps it camouflaged most of the time, but when threatened, it flips or arches to flash its belly like a warning sign. In this way, it combines camouflage with defense in one body.

The warning colors are not an empty bluff. Oriental fire-bellied toads secrete a milky toxin from their skin when disturbed, especially from glands on the belly and hind legs. A predator that takes a bite quickly spits the toad out after tasting the foul secretion. Scientists have identified compounds such as bombesin, a peptide that can upset a mammal’s digestive system. The toxin is strong enough to make predators vomit or feel ill, reinforcing the message that this is a bad meal choice.

For humans, the toxin is mild. It can irritate the skin or eyes if you handle a toad and forget to wash your hands, but it won’t land you in the hospital. Wild toads tend to be more toxic than captive ones, because their varied diet of insects and invertebrates provides the raw materials for stronger defenses. Some snakes, however, are immune and can eat these toads without issue. But for most predators, one bad taste is all it takes to remember.

When truly threatened, the Oriental fire-bellied toad doesn’t just rely on toxins. It performs a defensive posture called the unken reflex. In this dramatic display, the toad arches its back and lifts its legs, sometimes even rolling onto its back, to reveal as much of its fiery belly as possible. Motionless, with those vivid colors exposed, it dares a predator to test its warning. For many attackers, the sudden flash of orange-red and black is enough to make them retreat.

Other amphibians use similar displays, but fire-bellied toads are so closely tied to it that the reflex is named after them. While in this pose, the skin still secretes its toxin, doubling the deterrent. It is a last line of defense, a “look but don’t touch” performance that usually works.

Oriental fire-bellied toads have some quirks that set them apart. Their call isn’t a loud croak but a soft, bell-like chime, sometimes compared to a tiny bark. Unlike many frogs, they can’t flick their tongue to catch prey. Instead, they lunge open-mouthed at insects, worms, and other small animals.

For such a small amphibian, its lifespan is impressive. In the wild, they can live over 10 years, and in captivity, they often reach 10 to 15 years. With excellent care, some have even reached 20 to 30 years, remarkable for a frog only the length of a thumb. Their skin is also covered in bumps that look like warts, but these are glands and tubercles. Touching one won’t give you warts, though the secreted toxins can cause mild irritation if you’re careless.