WATCH: Wolf bites grizzly bear in the butt

A video of a wolf biting a grizzly bear on the butt at Yellowstone National Park has gone viral.

The footage, taken by Gary Gaston on Saturday, shows the wolf sneaking up behind the bear before chomping down.

"Look he got him right in the butt!" someone says before the wolf goes in for a second bite.

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The bear ended up biting the bear three times, according to Gaston.

"The bear sat down after it was bitten, then as soon as the wolf walked away it did too," Gaston told USA Today's FTW Outdoors.

Gaston says the video was taken at Crystal Creek near Slough Creek at daybreak.  He that there was a large animal carcass in the brush in the area that the wolf was probably trying to claim.