A person

And they keep releasing various portraits of the same purple haired girl (specifically this one) and the blonde girl who looks like Call from Mighty N°9 (ahem...) for some reason. ((And the overload of touhou portraits as well...))

I use this tag to search there, but haven't got anything this past few months 立ち絵

Ahhh...those two are from the VOICEROID program thingy! Yeah, there's plenty of talking portraits for them, as well as Touhou characters. I use these two tags to find my pictures, though:

MUGEN_STORIES_INFINITY - 立ち絵

I found some pretty useful ones for Rock Howard. They'll come in hand for the RP thread. :)