Fish (previously lily petal)
- "The student who gave me Francis... A spring afternoon I discovered a bowl on my desk, just a few inches of clear water in it. Floating on the surface was a flower petal... as I watched, it sank... just before it reached the bottom, it was transformed, into a wee fish. It was beautiful magic, wondrous to behold. The flower petal had come from a lily... your mother. The day I came downstairs, the day the bowl was empty, was the day your mother..."
- —Horace Slughorn regarding his pet fish Francis.[src]
Francis was a pet fish given to Horace Slughorn by Lily Evans when she was still a student at Hogwarts School of Witchcraft and Wizardry. Lily Transfigured Francis into a lily petal, set the petal to float inside a bowl filled with very little water in it, and left the presentation for Slughorn to find. When Slughorn found his gift, the petal sank down in the bowl and turned back into Francis, much to the Professor's delight. Slughorn kept Francis for many years, until the morning of 1 November, 1981, when he found Francis had disappeared. He knew this was a sign that Lily had died too.
- Harry Potter and the Half-Blood Prince (film) (First mentioned)