It is possible to get to the Frog and the Emerald as Tails in one step. After riding the trolley to the Aztec Forest, you will be standing up high on a platform overlooking the forest. Stand on the edge and look down to the left to see two trees sticking out of the canopy that are close together. Fly toward the trees and land next to the one that is closest to the ledge you jumped from. You should be standing on top of the canopy. Walk around the first tree until you fall through the canopy and end up right next to the emerald and the frog.