The Zodiac creatures were from monthly events where you had to complete a series of task in order to win them. After you win all of them, you get the Crystal-Zodiac Hybrid
Yea! Those were the enjoyable days when they actually bothered to come up with new and varied tasks for us to complete. It was so unlike the present day where we unwrap our presents only to discover that our parents had dug deep (or sometimes not) into our toy box to pull up an old toy and wrap it up as a gift for us, in the hope that it would be old enough that we wouldn't remember it LOL