The best improvement for a tile with an ancient forest is a castle while running the feudal contract civic. It's a good investment since you can get the techs fairly quickly.
Ideas for the new Worship category civics:
Trelocracy
Requires Octopus Overlords
+1 food from plantations
+1 hammer from fishing boats
-25% Gold
+100% GP birthrate
Medium upkeep
Shadow Court
Requires Council of Esus
+1 Hammer from Town, Enclave and Aduar
-25% Maintenance for number of cities
-25% Maintenance for distance from palace
+1 unhappy in every city
High upkeep
New compassion civics:
Favor the strong
Requires Warfare tech
+20% healing rate for units
+50% GP birthrate
+1 unhappy in every city
+1 unhealthy in every city
Medium upkeep
Pact of the Wild
Requires Commune with Nature tech
+1 Healthy in every city
+1 commerce for Camp, Forester and Fishing Boat
-1 commerce for Town, Enclave and Aduar
Enables production of the civs legendary beast unit (Animal Hero)
Here's some thoughts about the animal units. Take them with a big pinch of salt because I reckon I might be the only one who bothers with them.
Replace City Raider promotions with Flanking. It makes somewhat more sense to me that fantasy animal armies would be good skirmishers but lousy at sieges.
Wolf - Add 20% withdraw chance and +1xp/combat.
Wolfpack - Add 25% withdraw chance and +1xp/combat. Is it possible to change this unit into a "minifleshgolem"? That you could sacrifice wolf units and the Wolfpack unit gains their promotions? Upgrades into War Hounds (Dovellio UU).
Lion - Immune to fear.
Lion Pride - Add 1 First strike and Immune to fear. Same idea as with the wolf pack. Upgrades into Royal Pride (Malakim UU).
Gorilla - Add Woodsman I and +25% xp/combat. Would also make sense to make it nonagressive, like the Elephant. Upgrades into Grove Guardian (Ljosalfar UU).
Tiger - Invisible like the Giant Spider, +1 First strike. Upgrades into Battle Cat (Grigori UU).
Bear - Upgrades into Mage Guard (Amurite UU).
Polar Bear - Upgrades into Bear Rider (Illian UU).
Giant Spider - No city attack penalty (Can scale walls). Remove withdraw chance from Spider Totem. Upgrades into spider rider (Svartalfar UU).
Giant Tortoise - Add Defensive and Immune to first strikes. Tortoise grants defensive and +2 defense strength. Upgrades into War Tortoise (Lanun UU).
Sea serpent - Decrease strength to 6. Add 35% withdraw chance. Sea Serpent totem gives +15% withdraw chance and +1 movement. Upgrades into Serpent Rider (Mazatl UU).
Griffon - Add 20% withdraw chance.
Hmmm... Guess that leaves the Kraken and the Manticore for "totemization". End of rant.
