"Jabberwocky" by Lewis Carroll is generally considered a nonsense poem. It is full of words invented by the poet that are not found in any dictionary. However, there is enough conventional English in it to discern a simple story.
A father cautions his son to beware of the Jabberwock, which seems to be some sort of monster with "jaws that bite" and "claws that catch." The boy takes up his "vorpal sword." Although there is no explanation in the text as to what the word "vorpal" means, the weapon seems to function the same as a normal sword. The boy seeks the Jabberwock for a "long time." As he stops by a tree, resting and thinking, the Jabberwock, having "eyes of flame," attacks.
In the fifth and sixth verses the narrator makes it clear that the boy has killed the Jabberwock. "One, two! One, two!" indicates that the boy makes two thrusts with his sword. "Through and through" means that the boy's thrusts penetrate the Jabberwock and wound it. "Snicker-snack" is the sound that the blade makes as it strikes. Then the narrator clearly says that the boy leaves the monster dead and returns "with the head." This shows that he has slain the Jabberwock, beheaded it, and is bringing the head back as a trophy.
The boy's father asks if he has slain the Jabberwock, and apparently getting a positive answer, he hugs the boy and expresses his joyfulness. We see, then, that though parts of the poem are difficult to understand, it is clear that the boy kills the Jabberwock and returns in triumph to show his father the head.