Treelo is a lemur. He's performed by Tyler Bunch. As a lemur, Treelo loves swinging from vines and other things. He is very high energy. He loves feathers and has a collection of them. Treelo's excited mode of speech sometimes becomes incoherent. This sort of babbling is sometimes referred to on close-captioning as "Treeloese."
Treelo seems to be just a bit younger than the other kids in the [[Big Blue House]. He lives there when he's not playing outside. He apparently grew up there too and was raised by Bear, as Bear has memories of taking care of him when he was just a baby.