Fat Guys are a type of Shy Guy found in some Yoshi games. They are very rare and powerful. If Yoshi eats one of them, he will make a big egg. They appear in Super Mario World 2: Yoshi's Island. The Fat Guy will not be hurt if Yoshi jumps on him. Yoshi can defeat one by swallowing him. There are two types of Fat Guys: normal ones, colored red and green ones that run. Fat Guy also appears in the Nintendo 64 game, Paper Mario in which he asks for cake.
Fat Guys are uncommon enemies and come in two colors: red (they walk normally but run when stepped on) and green (which are always running). Fat Guys simply walk or run back and forth continuously, changing direction when they encounter a wall or a margin, unlike regular Shy-Guys which walk around and may stop and turn back on their own will. They are able to damage Yoshi if they bump into him, but Yoshi can attack them by eating and ingesting them. If spat back, they will resume their behavior.