1. Humans beings.
Size: 66 inches/172 cm in height, on average
Reside: Everywhere.
2. The Sea Wasp (or the Box Jellyfish).
Size: 8 inches/20 cm on each side, on average
Reside: Hawaii, Australia, Queensland
3. The Inland Taipan or Fierce Snake.
Size: 8 feet/2 meters in length, on average
Reside: South Australia, Queensland and Northern Territory boarder
4. The Saltwater Crocodile.
Size: 21 feet/6.4 meters in length, on average
Reside: Australia, Southeast Asia and Pacific Islands
5. White Sharks.
Size: 21 feet/6.4 meters in length, on average
Reside: Southern Australia
6. Scorpions, especially the African Spitting Scorpion.
Size: 5 inches/12 cm in length
Reside: South Africa, Zimbabwe, Mozambique and Botswana
7. The African Lion (or Panthera Leo).
Size: 10 feet/3 meters in length, on average
Reside: Africa, Gir Forest in India
8. Elephants.
Size: 9 feet/2.5 meters in height, on average
Reside: Sub-Saharan dessert of Africa, Southeast Asia and India
9. Hippopotamus.
Size: 11 feet/3.5 meters in length, on average
Reside: Primarily in Sub-Sharan Africa
10. Black Widow Spider.
Size: 1.5 inches/3.8 cm
Reside: piles of wood and firewood, outdoor toilets, boxes and other rarely used areas or objects
According to Purna Bhattacharya, TenMojo.com