The Leafiholly Woods is a great forest with giant trees and flowers. Mario and Luigi traveled this place during the events of Mario & Luigi: Rivals Quest. The Mario Bros. and the Wario Bros. meet Goomberto and Parakoopie that are lost in the forest. The forest is more maze-like, so the four heroes often had to split up to solve certain puzzles, but not that hard, fortunately, there are not that much enemies. Here, Wario and Waluigi learn more how to Punch and fight.
The place connects to Horlek Fortress via door and to Yoshi's Island via Warp Pipe. The Mario Bros. and the Wario Bros. must travel through the level to get one of the Shadow Shards and reunite Goomberto and Parakoopie, in order to succefully continue the quest. There's also a hidden Whacka.