Quantum Conundrum Wiki
Happy Little Trees

One of Professor Quadwrangle's earlier experiments was attempting to convert regular trees into Happy Little Trees. While the difference from normal trees isn't explained, the Professor does state that the experiment was foiled by "Happy Little Termites" and the whole area is now a "Happy Little Landfill."

This is a reference to the painter Bob Ross. On his show, he would say there are no mistakes and would often say the phrase "Happy Little Trees".