While I have included a few cards you wouldn't put in a drafting cube for being too narrow I have not included things like Ichorid and Nether Shadow, there are a couple of places in constructed cube formats where you can play those cards but you are essentially building around them and the decks are not even that good
For example, if you control Elsha of the Infinite ("You may cast noncreature spells from the top of your library") and Keeper of the Crown is on top of your library, you can cast Coronation of the Wilds, but not Keeper of the Crown
Ob Nixilis of the Black Oath Planeswalkers dont have creature types, but Ob Nixilis never really stops being a demon, right
While this may sound awful in principle, it can be paired with decks that benefit from doing so, like madness or other cards with flashback
Anything not a commander will be stranded there
There are a vast number of card sleeve types that you can use