A Robust Twilight Oak is a tree found in the Twilight Forest dimension. Towering above the surrounding foliage these huge trees range from 3 to 9 blocks in diameter, and range in height from around 50 to over 100 blocks tall. The trunks of these trees are hollow, with vines growing on one side, allowing a player to climb to the top. The trees can only be planted if there is enough room above and around the tree, and it can also be planted in the overworld. When grown, Cicadas and Fireflies may spawn on the tree. Getting Robust Twilight Oak Saplings is only possible if you find them as extremely rare loot in Twilight Forest dungeons.