The ground is made of Chocolate Covered White Brownie and White Brownie Blocks instead of Grass Blocks and Dirt, Chocolate Mushrooms and Chocolate Bars of all 3 kinds appear on the ground replacing flowers. Pools of Liquid Chocolate also generate on the surface.
Chocolate Bars and Cookie Ore also generate underground. Near the surface, pillars of Chocolate Blocks of all 3 kinds generate, extending up to 24 blocks below the White Brownie Blocks making the surface, as well as patches of Sugar. Pools of Liquid Candy may also generate underground near the surface.
Easter Chickens spawn in this biome, which is the only place where they naturally spawn.