Aurelia, the Poverty Witch. She has a destitute nature. Unaware of her own nature as a Witch, she attempts to live her life normally, but everything she touches turns to ash. She often still writes to her mother in heaven.
She resembles an ink blot with a large green eye, representing her envy (it is thought that this particular Puella came from an impoverished background, and originally wished for wealth or at least a laptop or cellphone like the rest of her classmates).
Minions: Eberhard, who resembles a pencil. His duty is to communicate, but with the advent of texting and email, hardly anyone can hear him anymore. But he still tries to make himself heard, and those who refuse to listen are stabbed to death with impunity.
Euclid, who resembles a ruler. His duty is to measure peoples' self-worth. Those who are deemed to be boastful and arrogant are promptly slapped to death by him.
Her barrier is a sheet of standard-issue lined paper, festooned with various antique school supplies on the side such as staplers and slide rules. Being literally a two-dimensional space, it is incredibly dangerous for non-Puellae who find themselves trapped inside, as they will find themselves crushed into two-dimensional form. (Puellae will be able to maintain their normal shape.)
To defeat this Witch, spare a thought in your daily routine for the poor, and contribute to charity regularly. Or bring a really big bottle of White-Out.
Yeah, this isn't entirely my idea (it originally came from /a/, and I found it on the Madoka wiki), but I haven't seen any Poorfag stories yet, so I thought hers had to be told, heh. That said, Aurelia's Witch name, her minions and her barrier description are mine. Didn't you like those writing exercises back in school where you would be given a picture or paragraph, and you had to expand upon them? I liken fanfiction writing in general to those.
Aurelia's name comes from the mother of St. Gemma, the patron saint of the poor and unemployed. Eberhard comes from the Eberhard Faber pencil company, and Euclid is named after the famous ancient Greek mathematician.
Feel free to write stories about her contracting or whatever.