With some clever abuse of the respawn mechanics and of the physics it is possible to get on top of the Pincers and use them to gain height and jump on the trees to get into pothole field and retrieve the Slime Key without needing to get the 5 Golden Leaves from Kanalet Castle.
Here's a tutorial:
Using a Tracy Boost you can get on top of some blocks to achieve the same as above but it is slower to do it that way.