A large, ugly, wet toad: In fairy tales, the toad is usually a malevolent creature, or a symbol of another character’s evil. These ideas exist outside the fairy tale genre as well.
In the fairy tale world, the concepts of beauty and ugliness generally reflect the good or evil natures of people. Thumbelina is beautiful, kind, and good, while the ugly toad has no qualms about kidnapping her.
The idea of Thumbelina as a siren and enchantress of males is here reinforced – she attracts the butterfly and then ensnares him for her own purposes, to facilitate her escape. The butterfly is drawn to her by her beauty, and in the end, as she realises, he may well die as a result of his attraction.
Thumbelina questions her own beauty. Given that a fairy tale woman is represented primarily or uniquely through her beauty, she is in effect questioning her very existence. She needs others to accept her beauty and so to be part of a society – otherwise she is desolate.
Thumbelina’s quest is ultimately to find a family, a society, and she is willing, at least initially, to consider all beings that she encounters.
Beauty and ugliness in fairy tales are often synonymous with the ideas of good and evil. Good characters, in particular the heroines and heroes, are beautiful. Beauty may also signify innate nobility, deserving of an elevated social position in the fairytale world. Thus unparalleled beauty sets the hero and heroine apart from the common man and woman. If a central character is ugly, it is usually either a temporary state of affairs, or a symbol of their evil nature.
The prince is clearly Thumbelina’s match because she finds him beautiful. The two mirror one another, in height and beauty, and are so destined to be together. As she looks into him, she looks into a mirror (arguably literally, for he is after all “transparent as if he had been made of crystal”) and sees a reflection of her own beauty. It is a very different moment from that in which she expresses despair at her own ugliness, having been rejected by the cockchafer. Her other potential husbands have been ugly in her eyes, and she could never have loved them.