His reaction was as swear-jar worthy as mine, so he went digging a little more into some of the other code relating to things that can walk, and by tacos, there it was, images as valid targets.
var/image/I = image('trail.dmi',loc=src.loc)
src << I
It works, he and I went 20+ years not knowing it worked, but it does. I have no idea what you'd use this for over an actual object, since it has no bounding, no density, nothing that would let it check collision, and it doesn't call image/Move() (which also exists but does nothing) so there's not a whole lot you can do with it.
Maybe some kind of variant of missile() without the pathing?
DM, you so crazy.