Now I want to know wether the rules allow you to stand perfectly inside your mirror image (don’t have a 5th ed./any other D&D ed. rulebook to check myself, sorry)… Because if it does (without going all wavy or otherwise distorting) and it casts a reflection this could be a fun “find the hidden vampire in this banquet hall with mirrors” scenario!
I heard them called “bats” because they flap around between different groups and are associated with darkness thus “shady”!