Mob Origins is an origins addon that currently adds over 10 unique origins, each with different powers and abilities. If you are looking to use some powers from this in a datapack, you can check out the wiki.
Missing Wilds strives to add all the content that was dropped or scrapped from the Wild Update. This includes things like fallen logs, and the birch forest changes from the concept art shown at Minecraft Live 2021.
Size Shifting Potions adds potions to the game that affect your size in various fun ways, such as shrinking you down, growing you up, or even making you super wide.
Glow Banners allows you to make banners glow by right-clicking them with a glow ink sac.
Extra Sponges adds new types of sponges to help clear out larger areas of water. It also includes a lava sponge for lava clearing.
Loading Screen Tips adds useful tips to the loading screen, which can be customized through resource packs.
Smelting Touch adds a new enchantment, Smelting Touch, which smelts items dropped by blocks mined with the enchantment.
Lucky Ducks adds cute little rubber ducks.
Spleaves re-implements the spleaves from the 2023 April Fools Update and adds some new features to them!
Overhauls the origin selection screen to show multiple in a grid for selection.
Adds content from the pumpkin moon event from terraria into minecraft.
Customizable Carts adds a variety of new minecart designs that can be customized with various parts.