Mammoth, or just a bear carrying a fish in its mouth? Mr. Snuffleupagus perhaps? As with all anomalous videos, the questions that need to be asked are things like: what happened before and after the video? Did they follow it, or at least alert authorities who would be able to track it?
In short: fun video, but a lot more information and context needed from serious investigators before anyone should treat it seriously. In the meantime, here’s a tabloid report.