Endemic to Cuba — only 4,000 individuals left. Reaches 3.5 m. Considered the most aggressive crocodile species in the world.

Behavioural studies show coordinated pack hunting and unusually aggressive temperament. Will leap from water to grab prey from low branches.

Critically endangered — restricted to Zapata Swamp and Lanier Swamp on Isla de la Juventud, Cuba.

Unique among crocs in pack hunting. Spends more time on land than other crocs. Hybridizes with American crocodile (genetic threat).

Up to 5 m. Greenish-grey with narrow, V-shaped snout. Found in saltwater and brackish coastal areas — unique among crocs in tolerating both fresh and saltwater.

More dangerous than American alligator. Several fatal attacks per year in Mexico, Central America, and Caribbean. Ambushes from water.

Coastal mangroves, estuaries, lagoons of southern Florida, Mexico, Belize, Guatemala, Honduras, Costa Rica, Panama, Cuba, Hispaniola, and northern South America.

Less docile than alligator. Excellent saltwater swimmer — has crossed 100+ km of open ocean. Active at night.

Stocky, aggressive shark up to 3.5 m. Uniquely tolerant of fresh water — found in Mississippi, Amazon, even Lake Nicaragua.

Top contender for most dangerous shark to humans. Hunts in shallow, murky water — exactly where people swim. Many attacks attributed to 'great whites' are actually bull sharks.

Shallow coastal waters, estuaries, rivers — Florida, Gulf of Mexico, Caribbean (Cuba, Bahamas, DR), Lake Nicaragua, Mississippi River, Pacific coasts of Mexico and Central America.

Aggressive and territorial. Tolerates salinity from 0 to 53 ppt. Attacks unprovoked more than other sharks.

Up to 5 m with vertical tiger-like stripes (fade with age). Eats almost anything — license plates, tires, and human remains have been found in their stomachs.

Second only to great white in unprovoked human attacks. Common in Caribbean and Hawaiian waters. Slow but powerful — strikes once and waits.

Tropical and subtropical waters — Florida, Caribbean, Gulf of Mexico, Hawaii.

Solitary, mostly nocturnal. Migrates long distances. Females birth up to 80 live pups.

Up to 3 m. The most commonly encountered large shark on Caribbean reefs. Often seen by divers in the Bahamas.

Generally non-aggressive, but documented attacks during shark feeding tours and on spear-fishers. About 30 unprovoked attacks recorded.

Coral reefs and continental shelves of the Caribbean — Bahamas, Cuba, Jamaica, DR, Belize, all major reef systems.

Diurnal. Apex predator on coral reefs. Often investigates divers but rarely aggressive without provocation.

Not a jellyfish but a colony. Distinctive blue-purple gas float with 30-metre tentacles trailing below. Drifts onto US Atlantic and Gulf coasts.

Excruciatingly painful sting causing whip-like welts. Rarely lethal, but several deaths recorded from heart failure or drowning after shock.

Atlantic and Gulf coasts — Florida, Texas, Louisiana, North Carolina; sometimes washes up by the thousands.

Drifts on wind via sail-like float. Cannot swim — entirely passive. Tentacles sting for weeks even after death.

Pale yellow-tan, 7–8 cm. The most venomous scorpion in North America. Glows brilliantly under UV light.

Neurotoxic sting causes severe pain, numbness, and in children — convulsions and respiratory failure. Antivenom dramatically reduces mortality.

Rocky deserts and palm oases of Arizona, southern Utah, southeastern California, parts of New Mexico and northern Mexico (Sonora).

Climbs walls, hides under bark and stones. Active at night. Sometimes enters homes. Can survive being frozen overnight.

Endemic to Cuba — up to 5 m long, the largest snake in the West Indies. Powerful constrictor with prehistoric-looking head.

Non-venomous but capable of inflicting deep wounds. Records of livestock losses; rare attacks on small children documented.

Endemic to Cuba — caves, dry forests, rocky scrubland, especially in Pinar del Río and the Sierra Maestra.

Hunts bats inside caves at dusk — strikes them mid-flight. Active at night, ambushes from elevated perches.

Disc up to 1.5 m with whip-like tail bearing a serrated venomous spine. Common in Gulf of Mexico and Caribbean — popular with tourists at 'Stingray City'.

Stings only defensively when stepped on. Spine drives deep, often breaks off. Steve Irwin's death is a textbook example of chest impalement.

Sandy and muddy bottoms of Gulf of Mexico, Caribbean, southeastern US Atlantic coast.

Buries in sand. The 'stingray shuffle' (sliding feet) prevents most stings. Eats clams, shrimp.

Reddish-brown ant 2–6 mm. Invasive from South America since 1930s; now infests southern US from Texas to Virginia. Aggressive when nest disturbed.

Stings cause burning pustules. Allergic reactions can cause anaphylactic shock — about 80 deaths per year in US attributed to fire ants.

Open sunny areas — lawns, fields, roadsides — across southern US, Caribbean, parts of Mexico.

Builds large mound nests up to 60 cm tall. Step on a mound, hundreds swarm out and sting in unison.