This toad will spawn near the Haze Maze Cave entrance after you have collected 12 stars. All main category routes include this star, except for 0/1 Star.
Grab the Toad star as your 13th or 14th star. This allows you to go directly to the exit door after finishing the stage. Go into Mariocam C-Down for lag reduction.
Grab the Toad star after completing the stage. This allows you to grab it on your way to the exit door. Go into Mariocam and spam C-Left for lag reduction.