More than You Ever Wanted to Know about Frog-spawn

In the first ten years that Harry Potter lived with the Dursleys, his Aunt Petunia never uttered a word to him about the magic ability of his mother, her sister Lily. When the truth finally comes out about his parents, this is the first statement Petunia makes about magic, and it must have summed up what in her mind were the most objectionable characteristics of her sister the witch. 

Knowing what we know about Petunia’s desire to be completely normal, it seems only natural that the ability to turn teacups into rats would offend her. After all, turning teacups into rats also turns the laws of physics and biology topsy-turvy, and is decidedly enough to upset someone determined to live a mundane life.

But why is frog-spawn mentioned in the same breath? What so disturbed the young Petunia Evans about Lily returning home from Hogwarts with pockets full of frog-spawn? At first blush there appears to be nothing particularly alarming about a clutch of amphibian eggs.

Of course, it could be that just the concept of bringing a gelatinous blob of animate goo into the house was enough to outrage Petunia, particularly as we know that as an adult she is compulsively clean. An algae-coated fish tank full of frog-spawn, then tadpoles, and finally young frogs, must have been low on her list of preferred home décor, more so if she had to share her bedroom all summer with Lily and her frogs. Petunia might have complained about any educational institution that exposed Lily to it, simply on the basis of messiness. Perhaps Petunia would have been more accepting if her sister had brought her a bar of Zonko’s frog-spawn soap (PA14) so that she could scrub those eggs regularly!

Another possibility is that observing frog-spawn develop was a summer assignment for students, which would have made it impossible for Petunia to ignore the fact that her sister attended that—that school. After all, Lily is not the only Hogwarts student who kept frog-spawn over the holidays. Ron also has a tank of the eggs in his room when Harry visited The Burrow during the summer between their first and second year (CS3), although it is hard to imagine Ron being very diligent about school assignments over the holidays.

Or perhaps Petunia had a surprise encounter with the frog-spawn. One hopes that Lily was bringing it home in some sort of container, a jar or bag that fit in her pocket, but there is also the possibility that the egg mass was loose and unprotected. It is easy to imagine nosy Petunia rummaging among Lily’s possessions without permission, trying to find incriminating evidence that would show her parents how wrong they were to be proud of their witch daughter. Petunia might have reached into a bulging robe pocket and grabbed a nasty handful of slime for her troubles. Did Lily deliberately fill her pockets with frog-spawn to deter just this sort of invasion of privacy?

Maybe the explanation is as simple as that Petunia had amphibi-phobia. But as is the case for socks and watches in the world of Harry Potter, there may be more to frog-spawn than meets the eye. There could be something about the very nature of frog-spawn that made it synonymous with everything Petunia despised about magic.

The answer might lie in the biology of frogs. Amphibians, including frogs and toads, are unusual in that they are vertebrates—animals with backbones—that undergo metamorphosis. Metamorphosis is the dramatic change from one form to another, and frogs epitomize this transformation. Their immature form, the tadpole, does not resemble in the least a mature frog. The tadpole is strictly an aquatic creature that breathes under water with gills; as it has no lungs it would die of suffocation out of the water. It has no legs and swims with a finned tail. It is herbivorous, with a mouth equipped for scraping surfaces to obtain its vegetable food.

The adult frog in contrast is equally at home in or out of water, breathing air through its lungs and although gill-less absorbing oxygen from water through its skin. It has lost its tail but has grown four legs with webbed hind feet that are perfect for jumping and swimming. It has even changed its feeding habits, becoming a carnivore with a long-tongued mouth ideal for catching insects.

This amazing change might have been what stuck in young Petunia’s mind, whether or not she was aware at the time that it was completely non-magical. The transformation of tiny, innocent, harmless tadpoles into jumping, gulping, croaking frogs may have symbolized for her the two other metamorphoses that were occurring at the same time. One was the transfiguration Petunia mentioned: Lily was taking harmless, innocent, pretty things such as teacups, and turning them into creatures that could bite, creatures that were not the least bit innocent or pretty.

The other metamorphosis was far more fundamental. As Lily learned to develop her magic abilities, she herself was changing from a harmless, innocent and pretty baby sister whom Petunia almost certainly envied (and possibly bullied), into a powerful young woman who had knowledge and abilities far beyond anything that Petunia could ever hope for, someone she now not only envied but feared.

When Petunia is first forced to speak of Lily’s abilities, she can not do it directly; she is unable to vocalize the name “Hogwarts” or even the word “magic.” Instead she apparently falls back on the analogy of those two other transformations to describe what to her was unutterable: the metamorphosis of Lily from little sister to witch.