Quest Groves spawn in the Enchanted Forest biome, which is one of the rarest biomes of the Twilight Forest. Even though the Enchanted Forest is quite rare, there are two or three Quest Groves in one biome.
Quest Groves have a Questing Ram located in the center of them. By feeding the quest ram every type of wool it will drop 1 diamond, gold, iron, and emerald block. Its main drop is the Crumble Horn.