The Rumble Pak was a peripheral by Nintendo that attached to the back slot of the Nintendo 64 Controller. The idea of a vibrating controller would later become a standard practice thanks to this contribution by Nintendo.
The device required 2 AAA batteries and could vibrate softly or shake violently. It shipped with Star Fox 64 to spread it faster. In The Legend of Zelda: Ocarina of Time, the player can acquire an item called the Stone of Agony, which (if the player has a Rumble Pak) would vibrate if they were near a secret or hidden item. This item came in the appearance of a stone Rumble Pak.