Well, like I said, the addon adds the warden mob and Sculk, let's talk more about this awesome mob 

The mob warden will be summoned by Sculk Shrieker if you activate it too much be careful if you crouch down it won't do any good as it can sniff you so if you summon a warden it will move away at least 15 blocks as the mob will burrow and disappear  

The mob warden has 250 health hearts and 30 heart health damage to the player.

Sculk blocks are naturally generated in the world if you don't. Be careful Sculk Shrieker summoned the warden 

To avoid the mob, make as little noise as possible as it may be suspicious of you and attack you. Distance yourself from the mob that will bury itself and disappear there you are safe

Mangrove Wood

Also added is Mangrove Wood items like fences stairs slabs fence gates doors and trapdoors

Mud 

Also added mud items like mud block, mud bricks, slabs, stairs and mud walls

Mangrove swamp

Mangrove trees and clay blocks are generated in the marsh. If you are in the latest version the frogs will be in the mangrove biome

Firefly

Fireflies are also added, they are naturally generated in the world and serve as food for frogs

Archeology

Added to archeology a really cool system where you find an archeological site and dig up earth and gravel to get items like pottery and ores 

you can find archeological structures around the world are remarkable for the bricks 

You can also put the ceramics in the pots and by putting a fire under a pot you heat it up leaving it like a ceramic pot 

IMPORTANT NOTICES 

YOU CANNOT TAKE ANYTHING FROM THIS ADDON BECAUSE EVERYTHING WAS MADE BY ME 

AT ANIMATIONS TEMPLATES AND TEXTURES WERE MADE BY @roxtro_animator ALL CREDITS TO HIM FOLLOW HIM ON TWITTER

to the aFor the addon to work correctly do the same as the images below