Tiny box jellyfish — bell only 1-2 cm. 4 tentacles up to 1 m. Causes 'Irukandji syndrome' 20-30 minutes after the (often unfelt) sting.

Symptoms: severe lower back pain, vomiting, sense of impending doom, hypertension, pulmonary edema. Documented deaths in Thailand, Philippines, Japan, Malaysia. ICU treatment.

Warm Indo-Pacific waters — Thailand, Malaysia, Indonesia, Philippines, southern Japan, increasingly common with ocean warming.

Nearly invisible in water. Drifts in coastal blooms during summer monsoon. Stings even after death.

Distinctive black mosquito with white lyre-shaped markings on thorax. Primary vector of dengue, yellow fever, Zika, chikungunya in tropical Asia.

Dengue: 4 billion at risk globally, 40,000 deaths/year, mostly in Asia. 2024 outbreak in Bangladesh killed 1,705. Bangkok, Manila, Karachi seasonal epidemics.

Urban areas of all tropical and subtropical Asia. Domestic breeder — flowerpots, water tanks, gutters, AC drips.

Daytime biter (unlike most mosquitoes). Bites multiple people per blood meal — spreads disease efficiently.

Largest hornet in the world — up to 5 cm with 6 mm stinger. Orange head, yellow-black banded body. Killed enough Americans in 2020 to earn nickname 'murder hornet'.

Sting delivers high-volume venom that destroys flesh. 30-50 deaths/year in Japan alone, mostly from anaphylaxis or multi-sting attacks. Can sting repeatedly.

Japan, Korea, China, Taiwan, eastern Russia, India, Nepal, Thailand, Vietnam. Forests, mountains, low elevation farmland.

Hunts honeybee colonies — a single hornet can kill 40 bees per minute. Attacks human nests aggressively at 5 m radius.

Up to 200 kg. Black with distinctive white V on chest ('moon bear'). More aggressive toward humans than American black bear.

Highest rate of unprovoked attacks among any bear species. Japan: 5-15 deaths/year, India: 10+ deaths in Kashmir alone. Mauls — targets face and head.

Forests from Iran east through Pakistan, India, Nepal, Bhutan, China, Japan, Russian Far East, Vietnam, Taiwan, Korea.

Mostly solitary, partly arboreal. Hibernates in north. More day-active than other bears. Attacks if cornered or with cubs.

Largest land predator in Europe. Males reach 350 kg. Mostly omnivorous; can outrun a horse over short distances and is an excellent swimmer and tree-climber when young.

Attacks rare but documented — about 10 fatal attacks per decade across Europe. Most occur when surprising a sow with cubs or a wounded individual.

Mountain forests of the Carpathians, Scandinavia, Balkans, Pyrenees, Alps, and Russian taiga.

Hibernates Nov–Mar in dens. Active at dawn and dusk. A sow defending cubs is the most dangerous scenario.

Brown mosquito 5–7 mm — the typical 'house mosquito' across Europe. Native, not invasive — but increasingly dangerous as warming climate amplifies disease cycles.

Primary vector of West Nile virus in Europe. Italy alone logged 430 WNV cases and 27 deaths in summer 2025 — equal to all US cases for that year. Spain, Greece, France, Romania, Hungary all reporting outbreaks.

All of Europe except the far Arctic. Breeds in any standing water — gutters, water butts, flooded basements, urban drains.

Bites mostly at dusk and night. Females hibernate in basements/attics through winter. The lifecycle from egg to adult takes only 7–10 days in summer.

Small, dark tick — the primary disease vector in Europe. Despite being only 3–4 mm, kills more Europeans annually than any other animal.

Transmits Lyme borreliosis (200,000+ cases/year), tick-borne encephalitis (3,500+ cases/year, ~30 deaths), babesiosis, anaplasmosis. The TBE vaccine exists.

Forests, parks, tall grass, urban green spaces. Most active April–June and September–October.

Quests on grass tips and twigs, latching on contact. Seeks warm, moist body sites. Feeds for 3–7 days before dropping off.

Up to 65 cm. Brown with darker oval blotches. The most common venomous snake in Japan — causes ~3,000 bites/year with 5-10 deaths.

Hemotoxic venom causes severe pain, swelling, occasionally kidney failure. Antivenom available; deaths now mostly elderly or untreated cases.

Forests, mountains, rice paddies of Japan (all main islands), Korea, China, eastern Russia.

Mostly diurnal in spring/autumn, nocturnal in summer. Often basks on stone walls. Used in traditional medicine — preserved in sake.

Up to 2 m — longer than most pit vipers. Yellow-green with darker blotches. Endemic to Japan's Ryukyu Islands (Okinawa).

Aggressive — strikes without warning. Hemotoxin causes severe tissue damage. About 50 bites/year on Okinawa; ~10% require hospitalization. Mortality <1% with antivenom.

Endemic to Okinawa and Amami Islands of Japan. Sugar cane fields, forests, ruins, sometimes inside houses.

Nocturnal hunter. Often climbs trees. Symbol of Okinawa — preserved in awamori liquor (habushu).

Up to 80 cm. Olive-brown body. The famous fugu — its liver, ovaries and skin contain tetrodotoxin, 1,200x more deadly than cyanide. Eaten as expensive delicacy in Japan.

TTX has no antidote. Causes paralysis with full consciousness — victims aware but unable to move or breathe. Treatment: ventilator until toxin clears. 50-100 cases/year in Japan, 5-10 deaths.

Coastal waters of Japan, Korea, China, Taiwan. Cultivated in special farms for restaurant trade.

Slow swimmer relying on toxin defense. Inflates when threatened. Licensed fugu chefs train 3+ years to safely prepare.

Second-largest amphibian on Earth — up to 1.5 m. Endemic to Japan. Lives in cold mountain rivers. A 'living fossil' essentially unchanged for 30 million years.

Powerful jaws with vomerine teeth deliver painful bite. Documented attacks on swimmers and fishermen. Bites won't kill but cause deep wounds requiring stitches.

Endemic to Japan — cold, fast streams of Honshu, Shikoku, Kyushu at 300-700m elevation.

Almost entirely aquatic. Active at night. Defends territory aggressively against intruders. Can live 50+ years.