Frog, Toad
The frog and the toad are often interchangeable symbols, but there are certain distinctions noted below. In general, the frog is seen as a masculine animal, while the toad is considered feminine, though this can vary. As a dream symbol, the frog generally has a positive connotation, while the toad tends to carry a more burdensome symbolism. Both are associated with sexuality, childbirth, and "emerging." They are also frequently used as animal symbols for children.
Metamorphosis
A distinctive feature of frogs and toads is that they are born as aquatic creatures, with gills and no legs, and undergo a transformation in which they develop legs, lungs, lose their tails, and move onto land. As we shall see, these animals are indeed closely associated with transformation as a symbol.
Since the frog and toad develop lungs, they must leave the water and move onto land; they cannot choose to remain in the water—or, symbolically expressed, in the unconscious. Their metamorphosis illustrates not only human evolution but also a compelled progression toward consciousness.
A fish, on the other hand, remains inexorably in the water and stands as a symbol further removed from consciousness.
Human Becoming
Jung suggests that the frog represents nature’s first attempt to create something resembling a human; a childish effort to bring forth something human-like at the level of cold-blooded animals – it is a cold-blooded little human. In fairy tales, the frog is a human, a prince who has yet to reveal himself. When the frog appears in dreams or stories, it can be understood as humanity in its chthonic aspect, a "nothing but"; a purely biological being. But this is only the outer shell of something much more beautiful and complete inside; the shell that will eventually be broken and cast off, through something like an initiation ritual.
Thus, the frog/toad is a symbol of healing that has been cast out, not accepted; the valuable in what seems worthless. It is precisely the ugly and repulsive that leads to redemption. (Visions, p. 544.)
Frog
In ancient Egypt, millions of frogs were born during the flooding of the Nile. The goddess Heqet was depicted as a frog or with a frog's head. She was the goddess of childbirth and death, and both she and the frog symbolized fertility.
The frog lives both on land and in water, making it a figure that brings contents from the unconscious. Frogs and toads are often seen as "moist" creatures and are associated with the moon and related areas such as moisture, witchcraft, and fertility.
Toad
The toad belongs to Mother Earth and was seen in some places as a helper during childbirth; it is "a cold and moist animal." Both frogs and toads have been used for magical purposes, including love potions and similar uses. However, because the toad secretes toxic fluid (and is considered a feminine creature), it has a stronger connection to witchcraft.
The toad possesses a dual nature of both life and death. It seems to rise from the earth and disappear back into it, as if it belongs to the underworld but travels between these planes. (Cf. Snake.)
According to Edinger, the toad is "a symbolic variant of 'the poisonous dragon'"; it represents "the philosophical earth" that cannot "sublimate," making it an expression of coagulatio – the earthly, material, and petrified. (Anatomy of the Psyche, p. 154)
In alchemy, the toad is the opposite of the eagle; it is earthbound, crawling, with a heavy head staring at the ground. But, as one alchemist (cited in Mysterium Coniunctionis, par. 2) notes, "were it not for the earth in our work, the air would fly away, nor would the fire have its nourishment, or water its vessel." The toad is, according to the same source, the foundation upon which the golden house (lapis) is built.
Change, Transformation
As a lunar animal, the frog/toad is a symbol of change. Grimm's tale "The Frog King" is one of many examples of how it represents something repulsive in the unconscious sphere that comes to meet the ego and offers transformation. According to Adler, "frogs in dreams often refer to transformation" (Studies in Analytical Psychology, p. 193). We recognize the archetypal motif in countless folktales, where the princess kisses the repulsive creature, and through this acceptance, it transforms into a prince, or where the prince marries a princess transformed into a frog, to ultimately release her.
Humanization – Unconscious-Conscious
The frog and the toad, in their body, are almost a caricature of the human form, which is certainly a reason why in folktales they were often humans who had been cursed.
von Franz says: “If an unconscious content appears as a frog, I always conclude that it could become conscious, that it even wants to.” The bodily similarities between the frog and the human further suggest the symbol’s “somatic” nature, she claims. (Redemption Motifs, p. 70.) The toad symbolizes the body, not spirit; the incompleteness of the human.
Thus, the frog/toad represents “an unconscious impulse that has a definite tendency to become conscious.” As a rule, one needs to help, to work actively with the content for it to become conscious, says von Franz. But the frog/toad represents in dreams something unconscious that has its own drive to become conscious; just as in the tales, it is something repulsive that only needs to be accepted. (The Feminine in Fairy Tales, p. 28.)
The animal can represent an underground, cold femininity; in a man, for example, an unresolved relational principle.
Alchemy
In alchemical imagery, the toad is prima materia, which (like the serpent and the dragon) has the philosopher's stone in its head (compare "Dragonstone" under Dragon). Examples of this motif are found in the alchemist George Ripley’s vision, but also in Shakespeare’s As You Like It: “Sweet is the benefit we are given by adversity. Like the toad, ugly and venomous, yet bears a rich jewel in its head.” The toad as prima materia fits the pattern: The valuable is found in the ugly, repellent, even toxic.
Alchemists associate the toad with the virgin; for instance, there are images where the toad (or frog) drinks her milk. In the Middle Ages, the toad was a symbol of the womb.