B. Pigeon 
Worm in a Jar [EPUB ebook] 

Witch-in-training Malee hadn’t intended to summon a shadowy, shapeshifting demon into her apartment, and she certainly never wanted to bind herself to such a creature in her blood.

But it’s too late now to reverse the magic she’s done, and the demon, who she calls Worm, appears harmless and helpless anyway. Malee agrees to send them back to their home, a task that she soon realizes might lie outside of her range of magical abilities. On top of that, she isn’t quite ready to trust Worm completely, and harboring a demon is a dangerous secret for a witch to keep…