The Collins Dictionary defines a card as a witty, entertaining or eccentric person. Being witty and entertaining can sometimes prove rather a challenge, but the eccentric bit should be no trouble at all. Just walk backwards. Or do some yodelling. Or wear a flower in your hair.
Actually, everyone seems to be doing that at the moment, so that probably doesn't count. Unless you're a man.
Don't be a yakuza, though. This is the Japanese for the worst possible hand of cards, an eight, a nine and a three (must be an interesting game) and also for a member of a criminal gang which goes in for illegal gambling, gun-running etc.
I suppose Lord Yarborough was a card, too. A yarborough is a hand at whist or bridge with no aces, kings, queens, jacks or tens in it. Lord Yarborough is supposed to have given odds of a thousand to one against such a hand occurring.
If this is true then he must have been a pretty awful card-player, because the odds are actually 1827 - 1. Or so I'm informed.
I should stick with the yodelling, myself.
Thing To Do Today: be a card. The word card comes from the Old French carte, and before that from the Greek khartēs, leaf of papyrus. The Greeks probably stole the word from the Egyptians, but so far no one's been able to prove it.