The golden retriever named Todd was on a hike with his owner Paula Goodwin in Anthem, Arizona, on Friday when the pair came across a rattlesnake.
Just as Goodwin was about to unknowingly step on the snake, Todd spotted it and jumped in front of his owner's leg.
Unfortunately his heroism did was not without consequences as the rattler bit him in the face, causing his cheek to swell dramatically.
Goodwin posted photos of the recovering retriever on her Facebook with the caption: 'My hero of a puppy Todd saved me.'
Todd was taken to the Anthem Animal Hospital for treatment and is expected to make a full recovery.