From the Super Mario Wiki
The Know-it-All Toad is a Toad that appears in Paper Mario: Color Splash. He is very smart, and knows a lot about Things. Some people call him a know-it-all as a way to insult him, though he says they should, as it is his actual name. He can be found in a trash can in the harbor district of Port Prisma. The Know-it-All Toad gives Mario hints about what Things will help him at the moment. Before Mario enters The Crimson Tower and when he gets a Game Over from a Koopaling's special move, Huey will tell Mario to speak with the Know-it-All Toad for guidance.