Wurtz

Condition:
When any card of suit Diamonds is played.

Description:
Player must say the phrase "Boxes taste like mush" upon placing their card down.

Failure:
"Failure to Wurtz."

Creator:
Archbishop

Trivia:
This rule is a tribute to Internet legend Bill Wurtz, who created such masterpieces as "history of japan", "song: new canaan", "song: i'm a diamond", and "history of the entire world, i guess".