In 2006, a ginger cat - also called Jack - chased a black bear up a tree in West Milford, New Jersey.
When the bear eventually climbed down, Jack the cat chased it up another tree.
The bear only escaped when Jack's owner called him into the house.
A mountain lion found it was no match for a Jack Russell terrier which trapped it up a tree on a farm in the US state of South Dakota.
The dog's owner, Chad Strenge, heard frantic barking near the family's farm in Colman, Moody County.
He discovered the 150lb (68kg) male lion, also known as a cougar, clinging to the top of a tree with 17lb (8kg) terrier Jack at the bottom.