Riddle twenty-one

Riddle twenty-one: Better thrown down that ________, Elwood

Difficulty: 5
Interest: 3

The title contains a lot of information about this one, as does the image. This is not a reference to the Blues brothers, but rather to the creator of a card game.

Fill in the missing word from the title to get your answer.

Next Level

*Spoilers*

Wikipedia is your friend for this one. Add the word 'card' along with his name if you can't find him otherwise. Once you find the game, find how they call a card that does not fit in this hand in that game. You've got your answer.