You should add koala bears. You should also have it so that there are bears that are terrorize randomly generated jungle villages, and they have posters up of the bears, and you get rewards from the village if you kill the bear, who acts as a mini-boss, thus making you a legend as you stroll across your world. You should also add in a new type of villager called 'The Gossiper', who knows stories about what you have done in other villages (such as killing the bears), along with whatever you tell them (a little box pops up with different options as to what you say). Or you can just add in koalas, which just basically hug trees, and add cuteness.

You should make a fish mod with some really small, decorative fish and large fish as well.

You should also make an otter mod. I actually know a lot about otters, like that there are 13 species of otter currently known, although the Japanese Otter is extinct. You could add their bones!

Fertilized block (crafted by combining bone meal and dirt). it looks slightly yellowish compared to normal dirt. when a sapling is placed on it, it will always grow the biggest possible tree for that 1 sapling (so instead of 4 blocks of wood, 6 blocks of wood, etc), and it will grow twice as quick.
when it is tilled, it becomes fertilized farmland, and crops grow twice as fast. this also happens jungle log blocks with cacao beans are put on such a block.

if it becomes a grass block, it will spawn long grass or flowers every few minutes, on itself and the 8 blocks immediately around it.

You could add rubber trees, but those are used in mods like IC2 already, and I wouldn't know what to do with it in your mod.
I suggest the Maple tree, which can be tapped by placing a treetap on a log block with a 'leak' (see the IC2 rubber trees). Then the treetap oozes rough maple syrup every few minutes or so. This can be distilled into fine maple syrup(5 rough for 1 fine), or made into sugar(3 rough to 2 sugar). Fine maple syrup will fill the hunger bar entirely, and will slightly speed the healing process, but will add a hunger effect after 10 seconds, that will take 3 units off the hunger bar.

You could add petrified logs, which can only be mined with a pickaxe. it can then be crafted into stony wood, which is used for the creation of a maple refinery. A maple refinery is more effective in making fine maple syrup, using a 1 on 1 ratio. it does take longer, though.

just some more ideas. pm me if you want more details.

Oranges and Bananas! More Apples and some Grapes!

Add a random villager re-designed to look hurt up. 50/50 chance he'll mug you. And he has a little hut made of dirt and wood in the forest.

More dungeons that can give you Accessories as rare loot (Example: Notch's Sandals give Speed II)
Sharks, Fish and a Kraken Boss
More Village species (Pigmen, Dwarves, Humans, Elves)

make the goat attack if provoked and lions and tigers should live in the plains biome
and bunnies are extremely fast p.s. if u already posted the mod then pls make my ideas an update p.p.s. what is the mod called pls answer

Ponds

If you added another type of village like a Dwarf Village under ground. Where they can trade for thing above ground they cant get down there EX. Stacks of wood for Iron.
You could add Knight "Castles" not very big (Almost like a strong hold but alot smaller)
They could have Iron gear and fight off evil Mobs.


(Edit) ~Can come up with more if you like the idea~

Still taking suggestions! A lot of these idea are cool but may take a while to add. I will try to add as much of your guys ideas as possible!

So that being said...
Anymore ideas?

I got some ideas! Add Mahogony trees, Cherry tress that drop Cherrys randomly when you break the leaves, you could add bushes that will have fruits on them like buffaloberrys, blueberrys, rasberrys, ect, ect, you could also add monkeys for the jungle, they are technacly forests right? You could add Lime trees that will randomly drop Limes, you could add foxes, deer, turkeys, you could also add tree roots, you can add alot of stuff!

hollow trees, tree houses, moss, thin branches (sideways kinda fence), fallen trees, fox holes, bear den, and or natural paths (tall grass all around, but a thin dirt path winds all over aimlessly).

Would love to know if you use one of these.


EDIT: ^That guy took half my ideas before I was able to post.

Ambient sounds, for one. rustling leaves, singing birds, and anything in minecraft already but enhanced.

fallen trees (in the jungle this is great)

moss (no sound of footsteps), + drops? slightly slippery on wood (only lo

undergrowth (bushes that work similar to cactus and sugar cane) that has a dense texture

seasons (and colors). falling leaves in autumn, bare decidous forest trees in winter (jungle is fine bcause of climate, and pine is unharmed becasue of evergreen nature)

prickly bushes that do slight damage if you walk trough (ideal for mob grinders)

Goblins, Single Leaves, BigFoot, And more

I know! here some ideas!

-Some kind of tree which when you destroy some mob called tree nymph comes out and attacks you!

-Foxes! just like ocelots but different skin passive mob kill chicken

-bushes that grow all over forests to make it look real

-randomly generated log houses

-add another type of minecraft world called forests in which everything is like trees and stuff

- You can make like fish that actualy swim aroun in the water and caves in which bears spawn and there can be different kinds of bears that are rarer than others

I got many many more ideas but this is getting kind of lond

Different types of grass, plants and vegetation associated with the selected forest type.

Any other ideas?

Trees? PLANTS?!

You can't forget poisonous plants... (what I am putting in my survival server...)
Example: Make 2 identical plants same textures and all, except one poisons you when you eat it for a long time (20 mins), with low damage. This will make a starving player think twice before he eats that strange colored jungle plants .

Food that hang off of trees

Add bushes (Random genning leaf blocks)

I have some ideas for your (awesome) Mod
1. Add different types of flowers, fruit and plants (like lettuce, banana, grapefruit etc.)
2. Add different types of birds (I don't know if that's possible to make though >.<)
3. Add Fish (maybe tropical fishes) and of course fishing nets then.
4. Maybe you could make some more tools made of the different types of wood.
5. Add a chainsaw and other woodcutting tools Which are created by different woods and ores
Thanks for (maybe) adding my ideas!

you could make fallen logs and moss and more types of mushrooms. Also elves and elven villages and like Scholesy said, bows.

Maybe a Random generated camp with campfire block etc where highwaymen spawn, And you could add new bows like longbow or maple bow or something as you add new trees, And make the trees proper forest trees not like the ones we already have, So like tall but slightly bigger leaf radius at the top. Make them spawn closer together aswell so there is a real foresty feel.

Also what about bears, and witches? (just ideas) Or.... randomly generated traps like pitfall traps

Ideas..here we go..
u can add a forest village like village on the top of the trees in those villages u can add markets and trade houses u can add more swords and armor for money u can add new mod for money that will be drop from killing mobs
more....
You can add games in the forest like .. parkour...

Ideas:
Lamb
Wind
Fish tank

My Idea:
Make the Tree Tall
Add animals like Tigers , Lions , Bunnies! , Goat , Wild Boars (They Attack)
Well thats all Ik Hope it helps you

Got some more!

Leaves can drop a more variety of items
Trees can spawn larger than usual
Some trees will take longer to break,because their sturdiness is higher.

More types of trees
More animals that live in the forest