The Ugly Duckling faces constant criticism for his appearance, making him feel ostracized and unworthy. He desperately wants to fit in with the ducks and other farm animals but is constantly reminded of his differences. His journey of self-discovery teaches readers the importance of embracing their individuality and recognizing their own worth, regardless of external opinions.

The story beautifully depicts the transformative power of time and growth. As the Ugly Duckling matures, he undergoes a physical transformation into a beautiful swan. This outward change symbolizes the internal growth he experiences throughout the story, ultimately finding acceptance and belonging within his true kind. The story instills a sense of hope, suggesting that even in the darkest of times, positive change and self-realization are possible.

The other animals' harsh treatment of the Ugly Duckling highlights the theme of prejudice based on appearances. Their mockery and exclusion showcase the cruelty that can stem from judging others based on superficial qualities. This theme serves as a reminder to treat everyone with kindness and understanding, looking beyond external appearances to see the inherent value within each individual.