Ugly Duckling is a Booster Pack available in Yu-Gi-Oh! 5D's Tag Force 4. It contains cards used by Yusei Fudo and Rally Dawson in the anime.
The Booster Pack is named after Hans Christian Andersen's fairy tale, The Ugly Duckling.
It can be unlocked by entering Kurumizawa's shop with either Rally or Yusei. Each pack costs 150 DP and contains 5 cards.