I realy don't believe fisher I see them all the time up here and they kind of hop when they move and definately not otter they are skinnier and longer and have alot more hump. I am going to say beaver, up here we have beaver leave there areas in the spring and this time in the late summer believe it or not I seen one today about a 1/4 mile from water we have them come into our hay fields when they leave there areas looking for a new home alot of this is due to low water levels because how dry it is and there looking for someplace for winter where there is high enough water level. When in open areas they move quicker than you think actually just like the video and are very aggressive.