From the Super Mario Wiki
Treevil Tidings is the first level in Dimble Wood in the Bowser Jr.'s Journey mode of Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey.
Before the battle starts, Larry and Wendy teach Bowser Jr. about critical hits and what strengths and weaknesses specific enemies have. The level has two battles. The first battle contains three green Koopa Troopas, five Treevils, and a Treevil captain. The second battle has three green Koopa Troopas, six Treevils, and a Treevil captain. After the battle, Bowser Jr. sets off to find the Giga-carrot. Meanwhile, in the distance, Fawful was discussing his plans with Midbus and Dieter, and was preparing his plan to use the Vacuum Shroom on Bowser, who was heading to Peach's Castle to get in the meeting on how to cure the blorbs at the time.