be resolved by the death of one of the combatants.

The external conflict in this story mainly exists between Rikki and the snakes. Nag, Nagaina, and Karait all are not happy with Rikki's presence, and they all try to either kill Rikki or get him to leave.

Another conflict exists between the humans and nature. Teddy and his parents seem to be trying to keep nature at bay. Teddy's mother is probably the most extreme in this sense because she doesn't even want Rikki around. She fears that he might bite Teddy. Teddy's father at least has an understanding that Rikki serves a valuable predator and prey function, but even the father violently beats on an already dead Karait.

As for an internal conflict, I recommend looking to Rikki's "man" versus self conflict. He is not a hulking superhero type that is completely fearless. He does legitimately worry about the threat that Nag and Nagaina pose to the family. He does have apprehensions about his ability beat Nagaina in her home. He knows better than to go after her in the hole, but he overcomes that fear to do battle with her.

The theme of "Rikki-Tikki-Tavi" is heroism—more specifically, the growth and development of a hero facing his first challenges, and the nature of his heroic qualities. In this, a children's story about an anthropomorphized mongoose is very similar to some of the greatest epics in literature, particularly Beowulf, the first part of which it resembles in structure. This is clearly Kipling's intention, since he begins the story by telling the reader,

This is the story of the great war that Rikki-tikki-tavi fought single-handed, through the bath-rooms of the big bungalow in Segowlee cantonment. Darzee, the tailor-bird, helped him, and Chuchundra, the musk-rat, who never comes out into the middle of the floor, but always creeps round by the wall, gave him advice; but Rikki-tikki did the real fighting.

Rikki, like all the great heroes, is a solitary figure, alone because he is without peer. The story begins with him a state of complete helplessness, apparently dead, and in truth very nearly so. Although the family rescues him and the other animals are on his side, he has to work out how to fight snakes for himself and rely on his own innate qualities in his journey to true heroism. These qualities include endless curiosity, alertness, and most of all, courage.

Rikki is also motivated by a strong sense of responsibility. He quickly adopts the human family, and makes it his mission to protect them, along with the animals in the garden. Like any hero, he soon discovers that he is exceptional and concludes that it is his duty to protect those who are not as strong and brave as he is.

The most important theme of the story is undoubtedly courage. Rikki has to show remarkable bravery in defending Teddy and his parents from the deadly cobras Nag and Nagaina. Taking on these two enormous snakes doesn't come easily to Rikki; he's genuinely scared of them. Yet he knows that he must overcome his debilitating fears if he's to protect the human family to which he's become so attached.

Although Nag and Nagaina are so much bigger and stronger than Rikki, he doesn't think twice about backing down. He could be forgiven for running away from them in terror, as so many animals have done in the past. But he doesn't. He stands tall in the face of danger and attacks the cobras head on. Rikki is victorious, as the snakes and their eggs lie dead, and Teddy and his family are safe. This is all down to the little mongoose's remarkable courage.

In his story "Rikki-Tikki-Tavi," Rudyard Kipling presents a battle-to-the death conflict between the mongoose Rikki-tikki-tavi and two cobras, Nag and Nagaina. The snakes are out to kill Rikki's adopted human family, but the little mongoose is even more determined to protect Teddy and his parents, and he does.

Little Rikki kills Nag first after foiling the cobra's plot to attack the humans in the bathroom. Then he kills Nagaina after bravely following her all the way down into her hole. He wisely destroys the cobras' eggs as well.

There are many themes in "Rikki-Tikki-Tavi," but the primary one, the one that seems to include all the others, is balance. Throughout the story, Rikki balances curiosity with caution, courage with practicality, and pride with humility.

As a mongoose, Rikki is a curious creature. This is how he meets his human family in the first place and how he discovers, as he explores the house and garden, the cobras' plot to kill his people. But Rikki, as curious as he is, is not careless. He approaches the snakes cautiously, for he is still young and not completely trained. He recognizes his limits and plans accordingly. He balances curiosity with caution.

Nonetheless, Rikki is a courageous mongoose. He bravely takes responsibility for protecting his family from evil in the form of snakes, and three times he saves their lives, willing to give up his own life if necessary to protect the people he has grown to love. The little mongoose is so brave that he even grabs onto Nagaina's tail and follows her down into her hole, knowing that he might never see daylight again. Yet Rikki balances his courage with practicality. He plans his moves carefully, trying to take the whole situation into consideration, including his risks and his limits. He knows when to push forward and when to back down.

Finally, Rikki balances pride with humility. By the end of the story, Rikki has every right to be proud of his accomplishments, and he is. He has defeated the evil cobras and protected his family. But Rikki is humble, too, and realizes that he has not destroyed all the evil in the world. He will be ready "with tooth and jump and spring and bite" to save the day again whenever he needs to and to continue to balance curiosity with caution, courage with practicality, and pride with humility.

The main conflict of Kipling's enduring short story is Rikki's inevitable battles with the cobras, Nag and Nagaina. Rikki is aware of the cobras' deadly abilities, but his natural instinct takes over on two fronts: A mongoose's mortal enemy is the cobra, and his own fears become secondary when one is near; and, his other duty was to protect the human family which had befriended him. His own safety was less important than these two instinctual urges.

The story contains several different themes. Courage vs. fear is one. Man vs. nature is another. Kipling's military background focuses on the importance of loyalty and duty, and the Darwinian theories of the survival of the fittest is yet another example.

The might of the British Empire vs. the simple ideals of Indian culture is another theme.  It expounds Kipling's belief of the superiority of the white man (represented by the British family as well as Rikki) over the Hindu people (symbolically epitomized by the evil Nag and Nagaina and the cowardly Chuchundra).

Or you may want to refer to the enotes theme link below.

http://www.enotes.com/rikki-tikki/themes

The central conflict is between Rikki and the snakes and takes place in and around the yard.

A conflict is a struggle between opposing forces.  This story is actually deceptively complex.  While on the one hand it is a story of a mongoose protecting people from snakes, it is also an allegory of British imperialism in India.  Yes, the conflict is between Rikki and the snakes.  Yet there is a larger conflict going on here.  The snakes’ territory has been encroached on by the people, just as the Indians have been colonized by the British.

There are many types of conflicts in literature.  The most common are character vs. character (Rikki vs. snakes), character vs. self (Rikki’s fear, and the snakes’ fear of that they will not be up to the task of confronting Rikki, and character vs. nature (Rikki being washed away into the garden).  There is also character vs. society.  That one is the one that caused this whole thing in the first place—it is the colonialism that causes the people to be in the garden, and gives Rikki justification to protect them.

Rikki is an ordinary mongoose who is washed into the garden one day.  Like any other mongoose, he wants to be a “house mongoose” one day.  That means he wants to live with a family.  All mongooses have one thing in common—they kill snakes.  The conflict between Rikki and the snakes was thus inevitable.

[Though] Rikki-tikki had never met a live cobra before, his mother had fed him on dead ones, and he knew that all a grown mongoose's business in life was to fight and eat snakes. Nag knew that too, and at the bottom of his cold heart he was afraid.

Nag asks Rikki an interesting question. It is only meant to be a diversion so that his mate Nagaina can distract Rikki, but it is worth considering.

``Let us talk,'' he said. ``You eat eggs. Why should not I eat birds?''

There are two issues going on here.  First of all, we are predisposed as humans to root for the fluffy, cuddly mongoose as opposed to the creepy snakes, even though the mongoose is the aggressor here.  Second, the snake and the mongoose both are just doing what their instincts tell them to do.  There is no right and wrong here.  There is just nature vs. nature.  In fact, Rikki will later kill all of Nagaina's eggs, both to prevent the cobras from growing up, and to distract her.  Where is the morality in that?  Do we pity her, or the baby cobras?

The character vs. society conflict comes from the fact that this situation only arises from the colonial backdrop.  These people are in this garden, trying to cohabitate with snakes, and in this country, because for some reason they feel that they belong there.  They feel that they can take what they want.  That is the nature of colonialism.  It is what humans do to animals, and it is what the British are doing to the Indians.  The garden is described as “only half cultivated” because the people cannot quite control their domain.  They are strangers there.

On its surface, this is a children’s story of a snake versus a mongoose, the good and brave versus the evil.  But there is no good and evil here.  There is only nature.  Rikki was not acting out of some kind of good will toward the people.  He was acting on instinct.  He was doing what he was born to do.  So were the snakes.  We as people only identify with one of those.

Rikki’s great war was the war against the cobras.

Rikki-tikki’s war was against the pair of cobras, Nag and Nagaina.  As a mongoose, it was his job to get rid of the snakes in the yard, as every good house-mongoose does.

This is the story of the great war that Rikki-tikki-tavi fought single-handed, through the bath-rooms of the big bungalow in Segowlee cantonment. Darzee, the tailor-bird, helped him, and Chuchundra, the musk-rat, who never comes out into the middle of the floor, but always creeps round by the wall, gave him advice; but Rikki-tikki did the real fighting.

Chuchundra helped him by telling him to listen for the snakes.  Darzee helped him by distracting the snakes and serving as a decoy, and by warning Rikki off.  However, Rikki was the only one who was able to kill the snakes.

Rikki washed into the garden and found himself in the care of a British family staying in the Indian bungalow.  He wanted to stay because the house was interesting, the people fed him, and it is a mongoose’s duty to watch out for people.

Chuchundra is not much help. He is too afraid to do anything.  He tells Rikki he should have talked to Chua, the rat, instead.  However, in talking to him Rikki hears a snake and knows that it is Nag or Nagaina. 

Darzee turned out to be very useful. He was a smart bird, and warned Rikki when Nag was there.

“Behind you! Look behind you!'' sang Darzee.

Rikki-tikki knew better than to waste time in staring. He jumped up in the air as high as he could go, and just under him whizzed by the head of Nagaina, Nag's wicked wife. 

Darzee’s wife also pretended to have a broken wing to distract Nagaina so that Rikki could go kill all of her eggs.  Rikki had two reasons for doing this. He wanted to eliminate the other cobras, and he wanted to have leverage to use against Nagaina.

Rikki manages to kill both cobras and the little snake, Karait.  Since he kills all of the cobra babies too, the people are safe in the garden.  If another snake comes, Rikki will get that one too.

Nag and Nagaina don't believe in live and let live. On the contrary, they see just about everyone and everything around them as a real and present threat. That includes the human family with whom the mongoose Rikki-Tikki-Tavi has been staying. Nag and Nagaina are concerned that if these humans discover their nest, they will surely destroy the unhatched eggs inside it.

Add to that the fact that the family are guarded and protected by a mongoose, one of the natural world's greatest enemies of snakes, and it's all the more important that the two king cobras should deal with this threat sooner rather than later.

They come up with a dastardly plan to attack the family at night and take Rikki out at the same time. This will be a war to the death, a fight to the finish; no quarter will be given on either side and none asked for. And Rikki knows this. Eternally grateful to the human family for taking care of him after he nearly drowned in a flood, Rikki is fiercely loyal to them and will do anything to protect them, especially the boy Teddy, with whom he's developed an especially close bond.

When the night of the attack comes, Rikki springs into action and kills Nag. But there's still unfinished business: Nagaina needs to be taken care of. So the very next morning Rikki ruthlessly hunts down Nagaina's nest and destroys all but one of her eggs. Nagaina is nowhere to be seen; she's on her way to the human family with the express intention of killing them. Rikki dashes off and manages to distract Nagaina just in the nick of time. After following her deep into her lair, Rikki then kills Nagaina. The war is now over.

An antagonist in a story is the enemy of the main character—who is called the protagonist and is usually the "good guy." In this story, the mongoose Rikki-Tikki-Tavi is the good guy because he is protecting the human family from the snakes that threaten them. The snakes—Nag, Karait, and Nag's wife, Nagaina—are the antagonists. Nag, the king cobra, is usually understood as Rikki's main antagonist.

Rikki must fight these snakes to safeguard himself and the human family. He gets into a daring battle with Nag after he learns that Nag is lying in the bathroom waiting to kill the human family and then get rid of Rikki. The mongoose is afraid because he has only killed one snake, but he knows he must defend the family, so he bravely fights Nag, getting hold of him by the neck and killing him before the big man appears with his gun.

In the story, "Rikki-Tikki-Tavi" by Rudyard Kipling, Rikki-Tikki, the mongoose  goes out to the garden and is very excited by all of the possibilities for hunting there. While outside, he hears a mournful cry and sees two warblers crying in their nest. Rikki-Tikki asks them why they are so sad, and they tell him that one of their babies fell from the nest and Nag, the snake, ate him. As they are talking, they hear a hissing sound, and there is Nag, a five foot long black cobra. Nag introduces himself, and as Rikki-Tikki is taking him to task for eating a poor baby bird, suddenly Darzee, the warbler says, "Behind you! Look behind you!" Just in time Rikki-Tikki jumps out of the way of Nagaina, Nag's snaky wife. Having missed their target, Nag and Nagaina leave--for now.

After being washed into the garden of the bungalow, Rikki Tiki Tavi is rescued by the family there and revived, and then his mission becomes quite clear. The family, particularly the father, speaks of the ability this mongoose will have to fight the snakes that are a real threat to them and their son.

When Rikki Tikki Tavi meets Nag and Nagaina it is clear that they will become his enemies, along with other snakes he might meet that would be a threat to the family that has adopted him, so to speak.

He kills Karait, the sand snake, but especially if the idea is that he "goes to war," it is with Nag and Nagaina as he must plan and there are a series of battles with them. He also enlists the help of Darzee and his wife as they wage their war against the king cobra and his wife. 

In the end, Rikki kills Nag, his wife and destroys their eggs and the war his over. His courage and skill win the day and safety for Teddy and his parents.