I think you may have been thinking of the site Haunted Hoax.  They may have done it on Skeptical Viewer, but I know Patrick Doyle also made ghosts very quickly in photo shop in his Haunted Hoax videos on youtube.  

I just watched this episode, and I am convinced that what is seen in the video is a lion. As soon as they were in the dark, the noise we heard was a lion's growl, not a roar, but a growl, did the sound come from the area they were in? Only the show knows that, but I say it was a lion's growl, no matter what the source.

I believe these are animals that someone has released and they are living in that area. There is probably more than one, therefore all of the carcasses, everyone seems to assume there is only one of these animals. I also don't think it's necessarily a black lion, due to the fact that when an animal is moving at that speed, there is a good chance that light will reflect and the animal will appear in shadow. This could be as simple as someone having them as pets, and then releasing them into this "wild" area of the UK.

When one compares this to that of a lion charging, it's pretty apparent that is exactly what we are seeing.

Cheers!  Renee' in the U.S.A.

The animal in the video is positively not a rabbit or hare. However, I could understand how if you concentrated on the slow motion portion that you could see a ressemblance. I did compare the link to the running boar video to the beast video and, again, can understand why someone would say they don't match. However, you are not actually comparing the same thing. The perspective in the boar video is from above while the perspective in the beast video is almost horizontal. Secondly, the boar is running normally while the beast is loping. If you are familiar with horses then this would be a canter or slow gallop. The most likely reason for this is that the ground is soft or the vegetation is thick enough that tripping would be a hazard. This is why the green screen test that FoF performed would not show a close match because no animal normally lopes on flat, solid ground (like in the test).

I can easily eliminate rabbit or hare because the leg lenth ratio is not even close. I can also eliminate horse for the same reason. I cannot eliminate pony on this basis because a pony with its shorter legs would be closer. I can understand why someone would think that the ruff around the shoulders ressembles that of a lion. However, I can also say that this is not a lion. The head is too low; lions don't run with their heads down. If this were a lion then the head should be the tallest point on the body; you can clearly see this in the video link of the male lion running. The snout of the beast in contrast is quite low. Ponies also run their heads up, so again, pony is out. For the same reason we can eliminate sheep and goats. Again, if you are familiar with horses then horses will sometimes walk or trot with their heads down but they don't lope and this is true of every other hooved animal I can think of.

This doesn't leave much except dogs perhaps and boars. Dogs do at times run with their heads down however dogs never lope with their heads down nor does any other member of the canine family. When wolves, coyotes, foxes, and dogs lope, they hold their heads up. What is particularly interesting is that if you stop the boar video at 7 seconds and stop the beast video at 6 seconds you get a matching profile. The shoulders are the highest point as would be the case with a boar and the snout is quite low (almost down to belly height) and this again matches a boar. I can also elminate almost all hooved animals on the basis of neck length ratio. For example, bison do have a ruff around their shoulders somewhat like the beast but their necks are too long.

Admittedly, the video is blurry and the clip is short and the gait (as I have mentioned) is an unnatural lope. Even so, I can say with great certainty that this is not a pony, goat, dog, lion, or rabbit. The common animal that matches is a boar. I'm baffled how they found someone who would claim that it "couldn't be a boar". I haven't found any characteristic of the beast video that would eliminate a boar. The length length, neck length, shoulder relative height, tail, and snout position are all consistent with a boar. The mane is certainly possible for a boar and the gait would match a boar that was loping because of the terrain.

As far as this being a lion, I can understand how a casual view of the video could make someone think it could be a lion, however, I'm puzzled how anyone could seriously make this claim. Lions eat a tremendous amount of meat everyday. An adult male lion is capable of taking down not only sheep but full grown horses as well. Lion tracks are quite large, much larger than dog prints. You might confuse lion tracks with bear tracks but never dog prints. Secondly, lions are not like cougars, leopards or jaguars which are shy and stealthy. Even in places where leopards are common, you can look for months without ever seeing a leopard. It is not unusual for documentaries to take 2 years to get enough leopard footage. However, lions are at the top of the food chain and are not particularly shy or stealthy. Lions often lay out in the sun in full view. Tigers are considerably more stealthy than lions (due to the forest versus savana habitat) however, again, as apex predators tigers are not shy. When an adult tiger escaped unreported from its compound it was detected, tracked and shot within two days of its escape. To think that a lion could somehow go unnoticed is nothing but fantasy.