Because of his deal with Asmodis, Zog decided to base an easter egg on the Lord of Hell.
A special unit—the Dragon Egg!
It costs only one hundred Magic Energy—as cheap as the Inferior Demon, the least expensive unit—and only one can be on the field at a time.
When it hatches, it's a Juvenile Dragon. It needs to constantly fight and grow, and can eventually develop into the Ancient Dragon, Zog!
Once fully developed, it becomes the strongest single unit in the game. Taking down an entire base with this one Dragon is no problem.
However, it's a total weakling until it reaches its adult form. Even as an adult, it's only about as strong as a Deep Prison Demon Refiner. Becoming an Ancient Dragon takes a very, very long time.
Considering the average match length for Red Alert players, it probably has no practical value in a real game.
By the time you finish raising Zog, your base has probably been flattened several times over.
That's why it's just an easter egg.
