Which one of the following snakes is known as the only snake species that actually builds a nest for its eggs?

Introduction / Context:
Most snakes lay eggs in hidden places or give birth without constructing any elaborate nest structure. However, there is one famous exception that is often highlighted in general knowledge and wildlife studies: a large, highly venomous snake that actually builds a nest out of leaves and other material for its eggs. This question asks you to identify that particular snake species from a list of well known snakes.

Given Data / Assumptions:

• The options are Python, Anaconda, Viper, and King Cobra.
• We are looking for the only snake that is well documented to build a nest for its eggs.
• We assume standard zoological knowledge about snake reproductive behaviour.
• We focus on typical behaviour in the wild, not rare or accidental cases.

Concept / Approach:
The King Cobra is widely recognised as the only snake species that constructs a nest. The female king cobra gathers leaves and other forest debris into a mound and lays eggs inside this structure. She often guards the nest for some time, which is unusual for snakes. Pythons do show parental care by coiling around eggs, but they do not build nests from external material. Anacondas and vipers do not construct nests in this manner either. Therefore, the correct answer is King Cobra, which is repeatedly mentioned in textbooks and nature documentaries for this behaviour.

Step-by-Step Solution:
Step 1: Recall that most snakes simply deposit eggs in sheltered places or are ovoviviparous, giving birth to live young. Step 2: Think of King Cobra, which is famous not only for its size and venom but also for building a nest of leaves for its eggs. Step 3: Consider Python. While female pythons coil around their eggs and may warm them, they do not typically build a structured nest using leaves and sticks. Step 4: Consider Anaconda and Viper, which do not display nest building behaviour like the King Cobra. Step 5: Conclude that King Cobra is the only snake known for actually building a nest, making it the correct option.

Verification / Alternative check:
To verify, think about common statements in GK books and wildlife documentaries where King Cobra is highlighted as the only snake that builds a nest. This behaviour is often used to illustrate that some reptiles, especially certain snakes, can show parental care and complex nesting behaviour. By contrast, descriptions of pythons focus on brooding the eggs by coiling, not on building a nest. Anacondas and vipers are discussed for other traits such as size or venom, not nesting. This consistent emphasis confirms King Cobra as the correct answer.

Why Other Options Are Wrong:
Python is wrong because, although it can show parental care by coiling around its eggs and possibly generating heat through muscular activity, it does not collect leaves and build a nest mound. Anaconda is incorrect as it does not have the nest building behaviour associated with King Cobra. Viper is also wrong; vipers are usually known for live birth in many species or simple egg laying without nest construction. None of these alternatives matches the distinctive nest building behaviour of King Cobra.

Common Pitfalls:
Some students may see Python in the options and think of its parental care, confusing egg guarding with nest building. Others may pick Viper or Anaconda simply because they are large or dangerous snakes. The key is to remember the specific phrase often used in exams: King Cobra is the only snake that builds a nest. Fixing this exact statement in your memory helps you avoid mixing up simple egg guarding with true nest construction and ensures you pick the intended answer.

Final Answer:
The correct option is King Cobra, which is the only snake species commonly known to build a nest for its eggs.