10 most difficult dan­ger­ous animals riddles

The saltwater crocodile is the largest of all living reptiles, reaching up to 6.3 m and 1,360 kg. It may be found from Northern Australia to the eastern coast of India.

Electric eel lives in muddy floodplains of Orinoco basin. It is well adapted to this low-oxygen environment: it can breathe atmospheric air using a vascularized respiratory organ in its oral cavity. In fact, electric eels must rise to the surface every 10 minutes and inhale, otherwise they die not having enough oxygen from the gill.

The praying mantis chews its victims in a manner similar to the way mammals do; however, its jaws close sideways, and not from the top or bottom like mammals' mouths. Mantis always eats the head first.

Ligers are the largest known cats in the world, reaching over 400 kg. In contrast, pumapards (hybrids between pumas and leopards) tend to exhibit dwarfism.

Siberian tiger males can reach as much as 3.5 m (11ft) in total length and 270–310 kg (600–675 lb) of weight. Lion males reach up to 250 kg.

The biggest recorded "beachmaster" male of the southern elephant seal was 5,000 kg (11,000 lb) and 6.9 m (22.5 ft) long. A bear can grow up to 1,000 kg - five times less.

The serval (Leptailurus serval) is a wild cat native to Africa. It is rare in North Africa and the Sahel, but widespread in sub-Saharan countries except rainforest regions. On the IUCN Red List it is listed as Least Concern.

The venom produced in the crural glands of the male platypus is not lethal to humans. However, it produces excruciating pain which does not respond even to morphine; sometimes the pain develops into a long-lasting hyperalgesia that can persist for months. Some biologists suggest that the venom may work directly on the brain's pain receptors. Other venomous mammals are small insectivores and vampire bats, which produce toxic saliva.

The ant named on account of its powerful and potent sting. It inhabits humid lowland rain forests from Nicaragua to Brazil, where it is often called "Hormiga Veinticuatro" or "24 (hour) ant", referring to the "waves of burning, throbbing, all-consuming pain that continues unabated for up to 24 hours".

Tigers living in the southeast Asia are semi-aquatic. They spend much of their time in rivers and feed on fish. Young tigers like to play in the water, and adults often take a bath just to keep cool during hot days.