This achievement can be gotten in Cloud Cuckooland.
Use the beak buster on the brown circular sections in the garden near the start. Two will contain seeds that you need to pick up.
Use the flight pad near Mumbo's skull and make your way around to two islands where you can plant the seeds. One is near the giant cheese wedge, the other is near Mr. Fit's 2nd location.
Then, find the real Mumbo's skull. There are two- one has a fake Jinjo on the lower level and one does not. The one with the fake Jinjo has the real Mumbo, the one without has a fake Mumbo boss fight. Take control of Mumbo (the real one) and make your way to a high exit from the central cave that leads outside to a purple racetrack. A Mumbo pad can be found on a ledge jutting from this purple path. Use the Mumbo pad to trigger a brief cutscene, after which the achievement will pop.