Regrowth

Regrowth allows villagers to improve their villages by cutting grass, removing leaves blocking roads (but not player placed leaves), repairing roads, building biome specific walls, and improving lighting around their villages.

Regrowth allows animals to actually eat grass, but also to optionally cause grass to regrow as the animals walk around (dropping seeds)

Regrowth allows coral to regrow slowly.

Regrowth allows creepers to grow and hide in tall grass, zombies to unintentionally knock over torches if they stumble past them, and skeletons to prompt the growth of giant underground mushrooms.