Mr. Geary has a grey and blue gear. He has eight teeth around his edge. His eyes are white with black edges. His nose is a dark blue gear with an orange centre. His eyebrows resemble that of Roger the Potted Ghost. His mouth is usually in a psychotic smile, but damaging him causes him to frown in pain.
Mr. Geary appears in the stage Mr. Geary's Factory. When Yoshi makes his way into the room, Mr. Geary is torn apart. However, he is revived when his remains are enchanted by Kamek, who wanted to make sure Yoshi does not get further. As Kamek makes his getaway, Mr. Geary reassembles his body. During his battle, Mr. Geary rolls, trying to crush Yoshi. Yoshi has to throw his eggs at the tape to damage Mr. Geary, which makes the boss angry and causes him to move around his arena faster. After he loses all his tape, Mr. Geary dies and falls into the lava. After the Yoshisaurs defeat Mr. Geary in his factory, they can advance to the final stage of story mode, The Great King Bowser.
He earned his name from "Gear", which fits him due to his appearance being similar to a Gear.