Character looks

CharacterLook is a character's appearance as the game composites the player's sprite: its layers - body, head, hair, each piece of equipment worn - each a sprite drawn at an offset, clipped and masked. Read the player's, carry it elsewhere as JSON (sprite ids are the same in every game from the same game data), and build another character's sprites from it with the game's own compositor: a companion, a mannequin, another player.

CharacterLook? look = CharacterLook.OfPlayer();
string json = look?.ToJson() ?? "";
// elsewhere, perhaps another game:
CharacterLook? same = CharacterLook.FromJson(json);

Building sprites

Build() draws to surfaces, so call it in a Draw event. The sprites are yours: Dispose them when done.

private CharacterLook? _look;
private CharacterSprites? _twin;

public void Load(ModContext context)
{
    // Draw a twin a tile to the player's right, in the player's own Draw event.
    context.OnCode("gml_Object_o_player_Draw_0", after: (player, _) =>
    {
        if (_look == null)
            return;
        _twin ??= _look.Build();
        if (_twin == null)
            return;
        Game.CallBuiltin("draw_sprite_ext", _twin.For(0, false), player["image_index"], player["x"].AsReal + 26, player["y"],
            player["image_xscale"], player["image_yscale"], 0, Draw.White, 1);
    });
}

private void ToggleTwin()
{
    _twin?.Dispose();
    _twin = null;
    _look = _look == null ? CharacterLook.OfPlayer() : null;
}