In the Beast Makers homeworld (not in any specific level!) there are 5 pairs of glowing mushrooms that look like this:
It's probably easier to find a video explaining where they are, but here are the locations (taken from IGN):
* Mushroom #1 can be located behind the Portal to Misty Bog, among the early islands of the swamp.
* Mushroom #2 is found behind the Portal to Wild Flight, down the well next to the hut where the Dragon Cleetus is found.
*Mushroom #3 is found at the base of the giant tree, close to the Portal for Tree Tops.
* Mushroom #4 is located at the base of the steep steps up the main pyramid, across from the Portal to Metalhead.
* Mushroom #5 can be found by climbing up the pyramid steps and walking around to the opposite side.