Utla was very good at spells, but she never cared much about potions. Unfortunately, the recipe was not very specific about "some furre of a cath". How much was "some" and - most of all - was the cat to be removed from the hair beforehand? Whilst considering this, she however noticed an amout of hair on the pillow, which she decided to use - very much to the relief of the cat, which spontaneously regained one of its nine lives.

(Edit, originally 7 lives, but the saying says nine.)