Would you be willing to draw two characters together or is that not a pertinent drawing skill to learn for you/inappropriate for the portfolio?
Nothing is inappropriate for a portfolio depending on the desired direction of it. I've seen people downright post porn as part of a portfolio, usually in the form of a photograph and a hyper realistic painting/drawing of said photo. As for my plans, I was job searching and stumbled upon a few videogame companies hiring. I'm trying to do something more appropriate for those... AKA backgrounds and/or more detailed characters more akin to what you'd see as part of the art of an RPG title.
Though none of the drawings in this thread are heading towards that.
This thread is for relatively quick requests, as in, something that takes me between 1 and 2 hours to make. To give you some perspective, my most time-consuming drawing has taken me around 10 hours up to the inking stage (no color), and it isn't uncommon to hear other artists to tackle 15 to 30 hour long works.
Anyways, just mention what you have in mind.
Tbh, fanart is harder for me to do than random inventions like the Pokemon drawings I made (it sounds backwards from what most artists would say, I know), but fanart is fine to request regardless since I'm doing this to get myself to draw out of my comfort zone to begin with.