Lord Yao (in Chinese: 妖魔王) is a giant boar-like demon. Yao fought Goku Jr. in the special; Dragon Ball GT: A Hero's Legacy. He is referred to as Lord Yao due to being the king of Mount Paozu, as well as a Demon Lord. Yāo (妖) means demon/monster in Chinese.
Arriving while Mamba and her goons were chasing Goku Jr., he fired a cannonball at Goku Jr. He then unleashed a powerful snout blast at them. The father bear started to attack Yao, but Yao grabbed the bear by his neck and proceeded to choke him by turning his hand into a root that wrapped around the bear's neck.
Then, his other hand turned into a blade, but, before Yao could kill the bear, Goku Jr. transformed into a Super Saiyan and quickly defeated the Demon Lord.
What remains of him is unknown, as he was last seen passing out under some rubble after Goku Jr. sent him flying into a rock wall. It is unknown if he was killed or if he survived.