A suspended animation kennel was a device invented by the early 21st century that allowed animals to go into suspended animation while their owners were away. When the animals woke up, it was like only a day had passed. Emmett Brown placed Einstein in a suspended animation kennel in 2015 after finding out about Marty McFly's children, Marty Jr. and Marlene, and retrieved his pet while Marty was running from Griff Tannen.