Yes, but I can only do B/W, HG/SS, and D/P/Pt style sprites.
...And adoptable site style sprites, but that's another story. I could probably do custom sprites styled like R/S/E, but those are really tiny...
I should also mention I can make animated character sprites.~
I can only make them with B/W Pokemon sprites, however...I haven't figured out how to animate custom sprites yet. xD