Frogs & Hell woofs.
Add their spawn eggs to the market.
Make a global mob cap for those 2 entities with In Control

This issue was moved by NillerMedDild to NillerMedDild/enigmatica2#620.

The issue isn't the spawnrate, the issue is that they don't despawn naturally. We've "fixed" it by setting a mob cap, meaning there can never be more than 20 frogs or fox hounds at a time. This at least makes the performance impact manageable.

While changes to config already have been made (#1540) in new release, changelog of new release of Quark (1 day ago) says that foxhound and frogs spawn rate got fixed. If this is true then maybe those changes will be unnecessary in next modpack versions.