Once-ler: So you want to know what happened to the trees? I didn't think anybody still cared!
Ted: Well, that's me! The guy who still cares!
After the song "How Bad Can I Be?", the camera is looking at the animals with 5 trees and the tree cutting machine behind them. As the machine reaches the 4th tree, the tree doesn't fall.
When Ted opens a drawer looking for a nail for the Once-ler, a Minion figurine (from Despicable Me) is shown in the drawer.