I wonder.
Could a card double as an object/enhancement AND a creature?
Like, the Ouroboros. I was thinking that it is a time-type creature, but due to its nature, of course, it has no attacks. Maybe its capability could be to enhance other time-types? And since the thing is immortal, you wouldn't be able to kill it, but you might only be able to use it once or a few times.
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)