The Bestiary says to defeat 40 to unlock location and description for ShadowFang Wolf, but the counter says it's 50, and it unlocked at 50. I might start a new run to check all the values another time, but you have some mismatch in there.
Every 50 victories against a normal enemy will give a boost to XP, gold, and item drop chance, maxing out at 150 wins.
At 60 victories against a normal enemy, gain access to more information about them
