From the Super Mario Wiki
Ludwig's Hunch is a level in Dimble Wood in the Bowser Jr.'s Journey mode of Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey.
As Bowser Jr. and the Koopalings trek on their mission to find the Giga-carrot, Ludwig starts to feel that something suspicious was going on. The level has two battles. The first battle has 3 red Para-Biddybuds, 2 green Para-Biddybuds, 3 Fire Stalking Piranha Plants, and a red Para-Biddybud captain. The second battle has six green Para-Biddybuds, two Fire Stalking Piranha Plants, and a green Para-Biddybud captain. After the battle, Ludwig, paranoid, tells Wendy that he felt like Bowser Jr. and the Koopalings were being watched, and fears that Bowser's Castle could be in trouble. Wendy, concerned, worries that Ludwig could blorb at any moment. Ludwig replies to Wendy that Bowser Jr. will be the Koopalings's responsibility until he gets back. He then leaves the squad without a word.