This datapack overhales the jungle with new mobs. Here are all the mobs that can spawn in jungles: Ocelots, Parrots, Pandas, Capybara, Monkey, Chicken, Wild Bumbo, Overgrown, Treant(surface), Cave Spider, Creeper, Enderman, Silverfish, Skeleton (caves).
Discord: discord.gg/JcFpyCC
Here is what each of the custom mobs do:

Capybara: Passive. Applies weakness 8 to all mobs nearby, befriending them. Can be lured with carrots and when feed heals the closest player.

Monkey. Neutral. Spawns holding a golden apple. Either kill it or drop a weapon for it to trade with you to get the golden apple.

Wild Bumbo. A special Wandering Trader for jungles. Only trade is 12 bamboo for 1 diamond. Only works once.

Overgrown: Hostile. A zombie that can poison you when you get hit. Drops clay, sticks, jungle saplings, rotten flesh, and poison glands.
Poison glands act like a poison splash potion but can also blind.

Treant: Neutral. Has 40 health, can plant saplings, and drops oak logs, leaves, apples and sticks. Deals a lot of damage. Have a reputation with players. Treants will attack other hostile mobs (besides overgrown).
Reputation:
Your reputation starts at 0
While you reputation is 0 or lower, treants are hostile.
Plant a sapling to increase your reputation (jungle saplings have greater impact)
Break a sapling to lower your reputation (jungle saplings have greater impact)
Reputation slowly goes down, and it has a min and max value.