The Unlikely Ones is a novel written by Mary Brown, first published in 1986. In it, a young girl with no name (referred to as "Thing Dear" by her comrades) and four animals - a kitten named Moglet, a crow named Corby, a toad named Puddy, and a goldfish named Pisky - are slaves to an evil witch who keeps them bound to her through enchantments on gems embedded in their bodies. The gems cause them crippling pain whenever they stray too far from her, but also grant them the power to communicate with one another.
When an angry mob of villagers comes and kills the witch, the prisoners make their escape. Even with their new freedom, however, the effects of the gems still plague them, so they set out to find someone who can lift the spell. This someone turns out to be the original owner of the gems, a dragon from whom the witch had stolen them. Along the way, they meet a knight, who had been cursed by their former mistress to always be rusty, and a unicorn with a broken horn.
The book contains some mature content, and so is only recommended for adult readers (though, especially Tolkien fans).