Bookend

Bookends are enemies in Super Mario 64. They are floating books with teeth. They appear in Big Boo's Haunt. Upon the player getting close, they rise into the air and throw themselves towards the player in an attempt to hit them.

Rainbow Ride
Some reports claim that Bookends can appear in the anomalous decorated house found in certain copies of Rainbow Ride. They have the same behavior as before, jumping out and attempting to fly at Mario in a straight line.