Big Guy
The title of this article is conjectural; an official name for the article's subject has not been found, so it has been given a fitting title by the editors. If an official name is found, then the article should be moved to its appropriate title.
Big Guys are Shy Guys that are fatter and bigger. They did not appear until Super Mario Advance. Strangely, they did not appear in Super Mario Bros. 2 but did appear in the remake.
They were going to appear in Yoshi's Story, making this their first appearance. However they were taken out of the game. Interesting, Big Guys were also going to appear in Yoshi's Story GBA where a stomp would turn it into a regular Shy Guy. However since the game was cancelled, Big Guys did not appear.
A robotic doll Big Guy enemy appears in Yoshi's Island DS. He is not a living creature though, however it appears that this Big Guy was once going to be living but in the final version of the game it was a doll.