• While some reptiles have longer lengths, others might weigh more.tape measure ruler image by MichMac from Fotolia.com
  
  Snakes, crocodiles, lizards and tortoises can be found in vastly different sizes. Determining which reptiles are the biggest depends on whether weight or length is considered; some reptiles may have a smaller length but a greater weight than others. All the living reptiles, however, are not as large as their now-extinct ancestors were.
  
  

Saltwater Crocodile

• The saltwater crocodile is the largest of all crocodiles.salt water crocodile image by Christopher Meder from Fotolia.com
  
  The average saltwater crocodile male measures about 17 feet and weighs around 1,000 pounds, though samples have been found to measure around 23 feet and weigh over a ton. The species is located in east India, Southeast Asia, and northern Australia. Because their hides are valued, they are often targets of poachers.
  
  

Green Anaconda

• The title of "largest snake" is under debate. The green anaconda is the largest snake as measured by weight, weighing around 550 pounds. The girth is around a foot in diameter and the snake extends to 29 feet in length. The females are much larger than the males of the species. The green anaconda is found in swamps and marshes.
  
  

Reticulated Python

• The reticulated python is the longest of all snakes.reticulated python image by Adrian Hillman from Fotolia.com
  
  While the green anaconda is the heaviest snake in the world, the reticulated python takes the title of the longest, measuring about 32 feet. It does not have as large of a diameter, and therefore is not as big around as the anaconda. The nonvenomous snake features a complex geometric pattern, and can be found throughout Asia.
  
  

King Cobra

• The king cobra can measure up to 18 feet.Cobra in Jaipur image by Cozminelu from Fotolia.com
  
  The longest venomous snake is the king cobra, which can reach to about 18 feet in length. During confrontation, they can raise their bodies straight off the ground and meet a human at eye level. The amount of venom they deliver per bite can be enough to kill twenty humans, though most will attempt to avoid humans when possible.
  
  

Komodo Dragon

• The komodo dragon is the largest lizard in existence.komodo dragon image by Mat Hayward from Fotolia.com
  
  The largest of the lizards can grow to ten feet in length and weigh over 300 pounds, making it the heaviest lizard on earth. The komodo dragon has a varied diet, consuming deer, pigs and even human remains. The species, located in Indonesia, is endangered due to destruction of habitat and poaching.
  
  

Water Monitor

• While the komodo dragon is the heaviest lizard, the water monitor can grow to greater lengths than the komodo dragon. Water lizards have a varied diet and are noted for their swimming skills. They are not considered endangered, though they are constantly targeted for hunting.
  
  

Galápogos Tortoise

• The largest tortoise, measuring about five feet long and weighing around 550 pounds, has a lifespan of about a 100 years. The animal is endangered as a result of nonnative species threatening food supplies and eggs. The tortoise consumes grass, leaves and cactus, and can survive up to a year without food or water.
  
  

American Crocodile

• South American crocodile specimens have been measured to be over 20 feet long.AMERICAN CROCODILE (Crocodylus acutus) image by PETER LAKOMY from Fotolia.com
  
  Located in North and South America, the American crocodile can reach up to 15 feet and weigh about a ton. Species in South America, however, have been measured to be over 20 feet long. The species is endangered, and various laws have been enacted to protect it, though they are rarely enforced.
  
  

Gavial

• The gavial can weigh over 2,000 pounds.two gharials image by Antonevich Anastasia from Fotolia.com
  
  Also known as a gharial, at a possible length of over 15 feet and a weight of 2,200 pounds, the gavial makes the list of the largest reptiles. This endangered species features a long snout, which adds length to its measurement from snout to tail. It is a carnivore, and lives for up to 60 years.
  
  

Argentinosaurus

• While current living reptiles extend to great sizes, none are as large as their ancestors. The Argentinosaurs stretched to about a 120 feet, the length of three buses end-to-end, and weighed around 100 tons. It holds the record for largest dinosaur ever discovered, mostly due to its long tail.