Yellow Belly is the Land Before Time name for Beipiaosaurus. Yellow Bellies only appear in The Land Before Time XIII: The Wisdom of Friends. The herd seen is lead by Loofah and Doofah is a prominent female in the herd. They also have a Wise One, Foobie. The herd is overall a very friendly, though silly, bunch who enjoy singing and dancing and have their own way of doing things. Their favourite song is Yellow Belly Bounce. After journeying across the Mysterious Beyond with Littlefoot, Cera, Ducky, Petrie and Spike the herd found Berry Valley, where they probably still live. Also, the herd hides by burrowing their heads and upper bodies into the ground and sticking their bottoms into the air so they resemble bushes (a method which unfortunately fails on hard ground).
Yellow Bellies in general are very fat, and the herd shown love berries.