Have a look at this video of a pretty daring dog!
A lost Californian black bear had wandered onto this housing estate near to the city of Los Angeles.
The big bear went for a swim in a backyard swimming pool but when it got too close one house, this family dog wanted to protect its home and chased the bear away.
The bear goes to hide in a playground, before it headed off back into the trees and nearby forest.
We hope this dog got an extra-tasty treat that night!