Gardens of the dead is a mod that adds new spooky biomes to the Nether, created for Spooky Jam 2022. Along with the new biomes, Gardens of the Dead also adds new plants and decorative blocks. Currently, 2 biomes are added, the Soulblight Forest and the Whistling Woods, pictured below. More biomes will (eventually) be added in the future, possibly with new mobs as well.