Magic domain is like riding a beast. Why can't I get BB and auxiliary BB? Is there any way?

That depends on what kind of riding pet baby you bring. Here I roughly divide them into the following three categories, the main purpose is to save money.

The first category: traditional magic beast merchants with double experience can sell there. It is suggested to collect gold coins with the philosopher's stone and then buy them with gold coins, which is much more cost-effective than directly buying O eggs from the system or riding pet eggs with the philosopher's stone.

The second category: constellations. Personally, I suggest buying two master babies from the magic stone store of the system (each constellation has two kinds of riding pets, one for a mage and one for a warrior), and then doing the constellation task (the babies obtained during the task are also two kinds at random). Official website has the specific process, so I won't go into details here. This category is suitable for non-RMB players.

The third category: special category, you must buy O eggs from the magic stone store of the system as secondary pets, such as all riding pets of flying category. These treasures are dealers in phantom beasts, not for sale. It is generally not recommended for non-RMB players to ride pets like this.

However, if it is in some older areas, it is recommended to buy one you like directly, which will save a lot of time, energy and magic stone.