Now, that's a loyal pal.In this very sad, yet heartwarming video, a sick-at-heart pooch is 'mourning' the death of a beloved but unlikely friend: A beaver named Beavis.According to YouTube user "Jack Bdead" who uploaded the video, Beavis and Bella the dog had played and lived together "for quite a while" before Beavis died last year."Bella has been in mourning for hours," the YouTuber said. Though first published when Beavis breathed his last in July 2012, the moving video has experienced a viral resurgence this week.