The title of the poem "The Duck and the Kangaroo" is justified because it accurately represents the main characters and the central theme of the poem.

The poem tells the story of a duck and a kangaroo who become friends and embark on a journey together. The title clearly highlights the two main characters of the poem, the duck and the kangaroo, giving the readers a clear idea of what to expect.

Furthermore, the title also suggests that the poem will explore the relationship between these two unlikely friends. Ducks and kangaroos are two very different animals, with different habitats, behaviors, and physical characteristics. The title hints at the unique and interesting dynamics that might arise from the interaction between these two contrasting creatures.

The title also signifies the central theme of the poem, which is the importance of friendship and cooperation. The duck and the kangaroo demonstrate their willingness to help each other and work together, despite their differences. The title reflects this theme by putting the two characters side by side, suggesting that they are equal partners in their journey.

In conclusion, the title "The Duck and the Kangaroo" is justified as it accurately represents the main characters and the central theme of the poem, giving readers an idea of the content and message of the poem.