Heh, I must've gone to town with the Carmela series, because looking back at this stuff I seriously decided to add some kind of flair, even for a bare minimum sketch like this. Sketchy though it may be, I still think it's nifty, so it stays on site.
Pictured, clockwise from the bottom is Carmela, Angelina, Raquelle and Maribel. There used to be some kind of backstory to the characters for this image. I'll reserve it for either a better picture or for people to read about some other way. I'll give you the first paragraph, though:
Despite being full of small Pokemon, Thunderwave Cave is quite dangerous considering all the unruly Pokemon (exploding Voltorb nonwithstanding) that live there. These girls don't actually live in the cave, rather in areas nearby, but they use the cave as a place to hang out, or hang low if any of them is in serious trouble. They refer to themselves as Las Cholas de la Cueva.