Create a humorous and action-packed scene of ninja sheep stealthily invading a medieval castle at night. The sheep are dressed in classic ninja attire—black suits, hoods, and tiny katana swords strapped to their sides. They use creative, acrobatic moves like jumping and rolling to sneak past guards and scale castle walls. The castle setting is illuminated by the moon, with torches casting a mysterious glow over stone walls and towers. The scene should blend comedy with action, showing the sheep’s unexpected agility and determination as they attempt to pull off a daring invasion.