We've started asking deeper questions of the monster taming data in this Exploring Monster Taming Mechanics series, but so far we've ignored the fact that these monsters can level up once we've tamed them. Their starting stats and abilities will not stay the same while the monsters develop, so we should take that into account when we're trying to find the strongest monsters. Monsters that can level up to higher levels are going to end up stronger than other monsters that may start out stronger but can't level up as much. And the way these monsters level up is by applying certain materials dropped by defeating other monsters in battle. We need to know when and where we can get those materials, so that is the subject of this post.