Barb-a-loots are bear-like creatures that live in the Truffula Valley. In the movie, while they appear dangerous and intimidating, they are really just harmless and innocent creatures, and apparently very lightweight, as Brett and Chet tried playing football with one. The Once-ler begins to form a type of friendship with the Barb-a-loots, even nicknaming one of them. But when his Thneed business grows, he then forgets about them and chops down the trees, which where Barb-a-loots get their main source of food, the Truffula fruits. When they were leaving the valley along with the Humming Fishes and Swomee Swans (including the Once-ler's mule, Melvin), it hurts the Once-ler, helping him realize the damage he has done.
Lou (the fat Barb-a-loot) is the biggest Bar-ba-loot in the Truffula Valley. He's often seen lagging behind the group. In the Blu-ray combo pack, he is featured with Pipsqueak in "Wagon Ho!", which is when he and Pip are having a joyride on the Once-Ler's wagon even though he told them not too, and "Serenade", which is when he battled against another male Barb-a-loot to win the heart of a pretty female Barb-a-loot.
Pipsqueak is a small, seemingly a baby Barb-a-loot that lives in the Truffula Valley. In the mini-movie "Forces of Nature", he, not knowingly, helped the Lorax to scare away the Once-ler out of the valley, but eventually the Once-ler found out and thus the Lorax's plan failed. He also gained a love interest, possibly now his soulmate, in one of the three mini-movies, "Serenade", where he is shown at the end of the video holding hands with the female Barb-a-loot which Lou and an un-named male Barb-a-loot battled against each other to win her love.
- Pipsqueak seems to be the Lorax and the Once-ler's favorite creature in all of the Truffula Valley.
- Pipsqueak's name means small, hence him being the only small Barb-a-loot in the entire film.
- The Once-ler's mother referred to them as "bears".
- In the Blu-ray combo pack, if you go to the makings of the mini-movies, the cast who worked with the movie reveals that the fat Barb-a-loot's name is Lou
- During the song "How Bad Can I Be?", the Once-ler refers to pipsqueak as a "puppy".
- Pipsqueak's nickame is Pip.