Yoshlossus is an orange Yoshi who has the ability to grow to immense sizes. He lives on Yoshi's Island, along with the other Yoshis. Yoshlossus likes to eat Super and Mega Mushrooms. He can stay in any size permanently. He can't shrink past 6.5 ft, which is his minimum size.
Yoshlossus's brother and rival, Yoshemoth, has the same powers. Their rivalry started out when Yoshiro, a flying Yoshi, befriended Yoshlossus, and asked his sister, Yoshara, if she could be friends with Yoshemoth. She refuses, because she doesn't like seeing Yoshis that are giant, and Yoshemoth became jealous that he doesn't get to have any friends. He says he's gonna find a friend himself, but most people are afraid of his gigantic size. That's when Yoshlossus's and Yoshemoth's rivalry started.
Yoshlossus makes an appearance in Yoshiro World, where he is first seen in World 2.