Here’s one Mia learned from a fellow improvisor fresh back from Paris. It focuses on heightening characters.

Players: 4+
Time: 5-10 minutes

Player 1 assumes a strong character and presents a “grail” to Player 2, and announces “I give The Holy Grail.”
Player 2 mimics and heightens the character, receives the “grail,” and says “I take The Holy Grail.”
Players 3 and 4 kneel to either side of Player 2 and, heightening the character to a level of absurdity, exclaim “He/She has The Holy Grail!”
Player 2 assumes a new character and starts the next round, passing the grail to someone else.