ROTFL - Its late, and that just struck me.MarkB said:I've just thought of a very weird loophole combining this concept with the Lurking Familiar feat, which grants your familiar Cover so long as it occupies your space.
Technically, a Medium spellcaster could ride a Large creature such as a troll to share its space, and certainly they could ride a Huge red dragon. With this feat, the polymorphed familiar gains Cover at all times, and can make a Hide check to conceal itself beneath its rider and escape notice.