[Works on Mobile] Click the breeding structure, then click two monsters. Wait for the monster you bred. Click on it once it has bred then wait for it in the nursery. Once it's done incubating, click on it and you have a new monster! Then you can start breeding all over again until you have them all. There is a 10% chance of getting a rare monster with a lower chance of getting an epic monster. If you breed or buy a monster while you already have that monster, it will replace the one you had but it could be a different type (rare, epic, etc.)
