"There are no unique monsters here, huh?" Bob went on and grew a bit disappointed.
The rachnid baboons were a letdown, it didn't entertain him as much as the monster he fought in the Northern Forest. Considering that the rachnid baboons were of a lower level, Bob didn't break any sweat swatting them down.
Still, it was a great combat experience for May. Unlike players, NPCs don't gain experience values. Their actual combat power is reflected in their levels, and that means that the more they fight, the stronger they'll become.
"Time for dinner?" Asked May, eager to eat the next dish Bob would come up with.
NPCs can grow stronger even without fighting monsters. They can level up simply by constantly practicing their art. This is also true for production class players, which is the total opposite of combat class players.
And that is why May was rapidly racking up levels.
[Level 143 May]