I found this story through the Fortean Times website this evening.

I knew of the tales surrounding the 'Angel' of Mons before, but this story was new to me. It sounds so wonderfully chilling (given the circumstances and location, the trenches of WW1) I wonder that someone hasn't made a movie about it.

The following is from the article:

That weird legend of No Man’s Land, the gruesome epic of the ‘hound of Mons’, has, according to FJ Newhouse, a returned Canad*ian veteran, been vindicated throughout Europe as fact and not fiction. For four years civilian sceptics laughed at the soldiers’ tale of a giant, skulking hound, which stalked among the corpses and shell holes of No Man’s Land and dragged down British soldiers to their death. An apparition of fear-crazed minds, they said. But to the soldiers it was a reality and one of the most fearful things of the world war.

“The death of Dr Gottlieb Hochmuller in the recent Spartacan riots in Berlin”, said Capt. Newhouse, “has brought to light facts concerning the fiendish application of this German scientist’s skill that have astounded Europe. For the hound of Mons was not an accident, a phantom, or an halluc*ination – it was the deliberate result of one of the strangest and most repulsive scientific experiments the world has ever known.

Teeth Marks in Throats.
What was the hound of Mons? According to the soldiers, the legend started in the terrible days of the defence of Mons. On the night of November 14, 1914, Capt. Yeskes and four men of the London Fusiliers entered No Man’s Land on a patrol. The last living trace of them was when they started into the darkness between the lines. Several days afterwards their dead bodies were found – just as they had been dragged down – with teeth marks at the throats.

Several nights later a weird, blood-curdling howl was heard from the darkness toward which the British trenches faced. It was the howl of the hound of Mons. From then on this phantom hound became the terror of the men who faced death by bullets with a smile. It was the old fear of the unknown.

Howl is Heard.
Patrol after patrol, during two years of warfare, ventured out only to be found days later with the telltale marks at their throats. The ghastly howl continued to echo through No Man’s Land. Several times sentries declared that they saw a lean, grey wraith flit past the barbed wire – the form of a gigantic hound running silently. But civilian Europe always doubted the story.

Then after two years, while many brave men lost their lives with only those teeth marks at the throat to show, the hound of Mons disappeared. From then on the Germans never had another important success.
“And now”, says Captain Newhouse, “secret papers have been taken from the residence of the late Dr Hochmuller which prove that the hound of Mons was a terrible living reality, a giant hound with the brain of a human madman”.

It's pure nuts but as I read it I got these vivid images of this entity skulking around, a horror upon horrors. Gave me the shivers :D

heres a link (hope it works ok, I don't know if you need to log in to view it though, here's hoping )