Gorgon

All Tyranid units change their [Hive Fleet] keyword to Gorgon. All units with the Gorgon Keyword gain the Allegiance: Gorgon special rule. The Allegiance: Gorgon special rule consists of the following rules:

• Hyper Adaptive Biology: Once per game, at the start of the Battle Round, you may change which Adaptive Physiology your army benefits from (see army special rules).
• Sustainable Consumption: If a Gorgon army does not slay more units than the opponent by the end of the game, you lose 1VP.