@Riger
fair enough. I also don't really remember if there are s for "small", and also why it's LL instead of XL. Nevertheless, when we already have D for "doppelganger", i don't think that any new species would be named with such close word as "mimc" or "copycat", since they are essentially all the same.
If that doppelganger really different from others, it would probably be named as "D subspecies", since the only thing that differed him from others is sigil usage (which also doesn't mean that it was different, just happened to possess a body of sigil user)