Rusty Crusty Musty Dusty

Drawn for EQD's NATG 3 day 10 theme: Draw a pony from a legend/Draw a pony with a story. I was pretty much stuck for a concept until a couple of hours prior to the deadline. In fact, to tell the truth I'm typing this part of the description ahead of time and still don't know what I decided to draw.
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Huh, turned out to be The Olden Pony paying some camping fillies a visit!
Shading, how does THAT work? I'm surprised my Sharpie didn't die of fright and/or exhaustion before this was finished.