Goddess of Whim

Level 3 LIGHT/Fairy Effect
950 ATK / 700 DEF

Once per turn: You can toss a coin and call Heads or Tails. If you call it right, double this card's ATK during this turn. If you call it wrong, halve its ATK during this turn.

Rulings – Yugipedia

Printings:

McDonald's Promotional Cards: MP1-003 (Super Rare) - 2002-12-20
Gold Series 4: Pyramids Edition: GLD4-EN008 (Common) - 2011-06-24
Legendary Collection 3: Yugi's World Mega Pack: LCYW-EN241 (Common) - 2012-09-29

Prices:

Cardmarket: 0.16 €
TCGplayer: $ 0.20