Chaser (April 28, 2004 – July 23, 2019) was a Border Collie with the largest tested memory of any non-human animal. Chaser worked with Professor John W. Pilley, at his home in Spartanburg, South Carolina, from eight weeks old, until Pilley's death in June 2018. She was trained in a formal research project. Chaser could identify and retrieve 1,022 toys by name.