A beast tamer wasn't a class or skill given by the system, but a term used by the players.
On rare occasions, aggressive monsters would show interest in players. If you didn't miss the chance, you could successfully tame the monster by giving it something to eat. The monster would then become the player's «Familiar» and serve as a valuable ally who supports the player in various ways. Players referred to those who had succeeded in doing so as beast tamers with a mix of praise and envy.
Of course, not all monsters can become familiars; only a very limited variety of small monsters could. The conditions to trigger the event weren't all that clear, but the only one that everyone was sure about was that the event wouldn't occur if the player killed too many of the monster type.
This was a rather hard condition when you think about it. Even if one tried to get a familiar by repeatedly meeting them, the monsters were aggressive and the player can't avoid entering a fight with them. In other words, if one wished to become a beast tamer, they would have to keep meeting with the monster, and if the event didn't occur they would have to keep running away. It wasn't hard to imagine just how annoying all that would be.
