I thought up the monsters in this while trying to think up a good Doctor Who monster.
He got down on his knees, relieved. He had finally escaped that madman, and now he was back in the forest. He stood up and looked around. The trees looked just the same - dark, impenetrable, easy to get lost in. He turned a full circle, but it was obvious he was lost. As he tried to find his way, he froze. There was a howling in the distance. "No," he said, "no. No! NO!" It was his greatest fear. The baron had found the empty cell and released the hounds. The Stalkers were coming.
They ran through the darkness, completely invisible save for their eyes. They were beings of dark matter, and they couldn't be seen. Nobody had ever seen more than the eyes, so their appearance was a mystery. But rumour had it they were like wolves, hunters, animals. Beasts with the mind of men. And they always found their prey.
The man ran through the forest, horrified. They were coming. He grabbed up a sharp branch and whirled, looking for blood-red lights in the dark. He whirled to find a pair of eyes. The main weakness that dark matter based life-forms have is that we are as invisible to them as they are to us. But evolution has gifted them with an ability to see both the dark and the light, as their eyes are matter, though they can only see red light. Which explains the glowing red light in their eyes. But how they can see each other, we don't know.
The man jabbed the stick at the eyes and it stabbed through one, then the other. The Stalker howled in pain, and the others came running. He jabbed the stick towards where he supposed the nose to be, for Stalkers have a keen sense of smell, but the stick snapped. For you see, dark matter can only interact with conventional matter via gravity. Therefore, dark matter can't touch matter, which makes the status of their eyes mysterious. But that is another matter. They can't touch us, so how can they kill us?
The Stalkers surrounded him, and he screamed. Soon, his arms began to stretch and a column of something like smoke emerged from his skin. The gravitational influence of the Stalkers was tearing him to shreds, atom by atom. Soon, his blood started to pool towards them, and his muscles and bones, until he had been atomized. Their eyes grew brighter from the atoms, and they feasted, then they returned to the mansion.