Eeries are an enemy which exclusively appears in the Ghost Houses in Super Mario World. They look like Blue Baby Yoshi's, with its eyes closed, floating in the air, lacking legs and boots. They also have ghostly arms.
 Johnnie's tips
They usually float up in down, in a straight line, in packs of over two. It is best to wait for them to pass by, unless you are a risk taker or Small Mario, where it is then easier to avoid these enemies.