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Shows up fairly often in the joke "Unglued" and "Unhinged" sets from Magic: The Gathering. For example, Ow's flavor text is "Have you ever noticed how some flavor text has no relevance whatsoever to the card it's on?"
Also shows up occasionally in the regular game. Lightning bolt was a card introduced in the early generations, and is widely regarded as being overpowered. It was never reprinted after the 4th edition... until the 11th edition, with the flavor text, "The sparkmage shrieked, calling on the rage of the storms of his youth. To his surprise, the sky responded with a fierce energy he'd never thought to see again."
Munchkin basically exists to hang lampshades, not only on the tropes of the genres each version is parodying, but eventually on itself. The "You start the game as a Level 1 human with no class" joke eventually morphed into "You start the game as Level 1 with no class and no style" and "You start the game as a Level 1 zombie with no Mojo (as this is a zombie movie, nobody has any class.)"