That's cool! I doubt these are unused sprites. I mean, 3 whole frames of animation? These guys are in a room somewhere in the game, there's definitely one remaining secret.
I don't know, I tried to find anything strange in the code. I did find a door component that was noted out, it was supposed to take you to a room with an id of Photo Booth. Though I can't find the room, and when I un-note it an error occurs. Though Rez might be somewhere, and room 15 is not noted. So room 15 may be accessible. I will continue to search for anything cool.
You might not know this, but there used to be a page where the developers had a dictionary of every single symbol within the game. Every picture had a full written explanation. Sadly the page seems to be down, or I can't find it. It might have been useful since the drawing on the map in town has a 3 symbol message from the howl person.