Shy Guy Goes Overboard
From the Super Mario Wiki
Shy Guy Goes Overboard is the first secret level of Chucklehuck Woods in the Minion Quest: The Search for Bowser mode in Mario & Luigi: Superstar Saga + Bowser's Minions. In order to obtain this level, the player has to use certain amiibo to unlock it.
The level consists of mostly Shy Guys, Fly Guys, and Spear Guys and has three battles. The first one has five Fly Guys at the front, two Shy Guys at the back, and a Shy Guy captain. The second battle has three Fly Guys at the front, four Spear Guys at the back, and a Fly Guy captain. The third and final battle has two Fly Guys at the front, four Spear Guys at the back with a single Shy Guy in the middle, and a Spear Guy captain.