What five character traits describe Nag in "Rikki-Tikki-Tavi"?

Nag is the male cobra in this story. When readers first meet him, they find out that he has brought great grief to the tailorbird family by eating a baby bird that fell out of their nest. This establishes him as a cruel villain. He continues to demonstrate his cruelty by plotting to kill the man, woman, and boy. 

Nag is also crafty. In his first meeting with Rikki, he tries to keep him talking so that Nagaina can sneak up behind the mongoose and strike. He decides to kill the man by lying in wait for him in the bathroom of the bungalow so that the man will be unarmed and taken by surprise. 

Despite how cruel and crafty he is, Nag is fearful. Upon first seeing Rikki, because he understands how deadly mongooses are for snakes, "he was afraid." When he questions Nagaina about the necessity of killing the humans, it is doubtful he does so from any kindness in his heart toward them. Rather, he saw the man beat Kurait with a stick, and he does not want to receive the same treatment. Therefore, he hides in the bathroom because "when he comes in to bathe in the morning he will not have a stick." He sees that ridding the house of humans will keep him from having to face Rikki in battle: "There is no need that we should hunt for Rikki-Tikki afterward.... The bungalow will be empty, and Rikki-Tikki will go."

The snake is also pompous. To introduce himself to Rikki, he makes a self-important speech about the "great god Brahm" who made him to look as imposing as he does. He then challenges Rikki to "look, and be afraid!" 

Finally, the snake is unethical. When Rikki challenges him on the ethics of eating "fledglings out of a nest," Nag responds, "Let us talk. ... You eat eggs. Why should not I eat birds?" His reticence about killing people is easily overcome by his wife when she points out that killing them will mean that they will become "king and queen of the garden." 

Nag's negative character traits contrast with the positive traits of Rikki, who is ethical, brave, humble, smart, and protective of the humans and the other animals.

Describe the character Rikki-Tikki-Tavi from Rudyard Kipling's "Rikki Tikki Tavi".

The first thing to note is that Rikki-Tikki-Tavi is a mongoose rather than a person (it should be noted that a majority of the characters in this story are animals: consider the two tailor-birds, Darzee and his wife, or the villains of the story, a married pair of cobras). As one can easily infer from the existence of marriage among the animals, these animals have been anthropomorphized so that their personalities are more in line with human beings than they are with wild animals.

Rikki-Tikki-Tavi is a young mongoose whose personality is best defined in terms of his bravery. This bravery is established both in his conduct around humans as well as in his fights against the snakes. He isn't fearless (for example, consider the scene where he kills Nag: he's very much aware in this moment that one wrong move can leave him dead), but he's described and characterized as being a fighter. He is very much a hero to the other animals and a protector to the human family he falls in with.

What kind of animal is Nag in "Rikki-Tikki-Tavi"?

Nag, and his wife Nagaina, are snakes.  Specifically they are cobra snakes.  Big, black cobras to be really specific.  

While wandering around the garden one day, Rikki-tikki comes upon Darzee and his wife.  The two Tailorbirds are in their nest crying.  Being a curious fellow, Rikki-tikki asks them what is wrong.  

"We are very miserable," said Darzee. "One of our babies fell out of the nest yesterday and Nag ate him."

Rikki-tikki immediately expresses his sympathies, and then asks about Nag.  Rikki-tikki says that he is new to the garden and doesn't know who Nag is.  Darzee and his wife are kept from answering the question, because Nag immediately sneaks up and surprises Rikki-tikki.  

Darzee and his wife only cowered down in the nest without answering, for from the thick grass at the foot of the bush there came a low hiss--a horrid cold sound that made Rikki-tikki jump back two clear feet. Then inch by inch out of the grass rose up the head and spread hood of Nag, the big black cobra, and he was five feet long from tongue to tail.

Nag doesn't even let Rikki-tikki ask for his name, because the big, black cobra immediately announces who he is and how great he is.  Obviously humility is not one of his characteristics.  

"Who is Nag?" said he. "I am Nag. The great God Brahm put his mark upon all our people, when the first cobra spread his hood to keep the sun off Brahm as he slept. Look, and be afraid!"

Rikki-tikki is momentarily frightened by Nag, but his fear doesn't last long.  Rikki-tikki soon remembers that his mother fed him dead cobras when he was baby.  Rikki-tikki figures that he has nothing to fear from something that is normally his food.  This entire introductory scene sets up the conflict between the likable, heroic mongoose and the detestable, evil cobras.

How would you describe the character of Nag in "Rikki-Tikki-Tavi"?

The reader first learns of Nag from Darzee, who tells Rikki Tikki that Nag ate one of their babies, and then suddenly Nag appears.

He is described as being five feet long and as wicked as any snake ever was. He has the marking on his hood that looks "like the eye part of a hook-and-eye fastening." He is very strong and has had free reign of the garden for quite some time. Even the humans are frightened of him and Nagaina, his wife.

He is ruthless, willing to kill the man to try and regain control of the garden. He is so strong and powerful that Rikki Tikki knows that once he has hold of his head, he cannot let go. And nowhere else could he bite him and do damage; Nag is simply too powerfully built.