A poker game in which all of the players are terrible, make stupid bets, calls, etc. No skilled required to play, just pure dumb luck because the players are so clueless.
A donktress is a woman that carry's behind her a large rear endlike that of a female donkey. It is a common used term among the Mexican peoples of the Yucatán peninsula.
Hey Pedro, take a look atthe ladyover there, see how much she is carrying in her ass, she is a donktress.