Last night-or rather this morning-I had a dream that had similarities to another dream from about a month ago.

The dream from a month ago was an elaborate and complete story inspired no doubt inspired by a recently watched historical-romance Bollywood film and Diablo 3.
In it a young warrior fled his home to escape being executed for loving and being loved by a princess of a kingdom besieged by a powerful and malicious force that had already consumed a third of the kingdom in a persistent darkness cast by rainless, black clouds. The warrior flees into the dark and is soon attacked with teeth and claws by monstrosities barely visible in the gloom. After fighting for an unknowable amount of time he collapsed from exhaustion but instead of tearing him apart the creatures disappeared. When he woke up a silver plate of mushrooms and a silver goblet of water,tainted with something that may have been blood, was placed near him by an unseen benefactor. After weeks of a cycle of fighting, collapsing from exhaustion, and being nourished by mushrooms and the tainted water he began to see in darkness. At last he could see in total darkness.
After defeated the evil lord of the darkness he tried to return home, but at the boarder of the cloud cover he saw in normal light that his skin had turned bleach white and the sun burned him.
The dream continued to a happy (happier) ending but that is beside the point.

Last night I dreamed of a young woman with blonde hair that was ostracized by her community because of her weight. Two stags ran out of the forest, intent on rejoining their herd on the other side of a small town. In the dream I was the younger of the two. The girl ran after us. I could feel her desperation to escape her misery and join us in the forest. The other stag and I silently agreed to be her guides into the wilderness and we slowed as much as we dared. We even stopped to wait for her a few times, but we could not slow down too much or else hunters in the town might kill us, perhaps only for the trophy rack of antlers sprouting from our heads. Despite her best effort the woman collapsed from exhaustion near the treeline.
I was no longer either of the deer at this point, I was an audience to my dream. The deer took pity on her and nuzzled her to consciousness and led her to a bowl on top of a pedestal. In the golden colored bowl was muddy water. The water was grey but still the woman drank it, and I felt the grit on her teeth. I was semi-lucid and I tried to clean the water, but it was in its nature to be unchangeable.
The woman, however, was refreshed and joined the deer in the forest. At the end of the dream I watched a herd of deer travel through thick forest, and I caught fleeting glimpses of blonde hair and white cloth through the leaves and tree trunks.

Any ideas about the tainted water. Why blood in a chalice and mud in a bowl? Both were escaping but for different reasons. Any ideas on the recurring themes?

In looking at your response to Silmendo, I see that you have some familiarity not just with dreams but with Jung. (Perhaps, in one case or the other, more than I do.) The comments I make here are intended to be general. If you find them relevant, you might reply and we can talk further.

I watched neither the historical romance nor Diablo 3, but it appears they've led your dreaming mind to give you what amount to two quests. In both, the hero/heroine is forced into exile for reasons that involve no real sin on their part; but which violate the mores of the society in which they've lived. Both initially seek refuge in - or at least find themselves in, or are driven to - a realm which that society has taught them to see as strange, hostile, threatening. Yet, each has the potential to be revitalizing; and to teach lessons that that waking society cannot.

In the first dream, I'm not so sure that it's all that "evil" a lord you're fighting. How much of him is evil per se; and how much is "evil" only in the sense that what I'll call Waking Society finds love of a princess or being overweight evil. (In this respect, consider our society's recent fixation with obesity; and how many of the public pronouncements seem to equate it with a moral failiure on the part of the obese person. Further, consider how many people would not consider it evil to destroy a beautiful stag simply to get a set of antlers to hang on a wall.) The cave, the odd food and drink, and the lord you combat and, most especially, the darkness are pretty obvious metaphors: you (vicariously through your hero) are in the Realm of the Shadow; and a crucial point Jung makes is that there is much good in the Shadow. In simply dismissing it as an Evil Lord, you stand to lose much of true worth, value and - if my experience is any guide - wisdom. Again in the case of you hero (which is to say, you), it's not victory you - or that lord - are after. There is conflict; but your enemy sustains you. Strange though the mushrooms and (apparent, perhaps real) blood are, they symbolize the very "food" that enables you to adapt. In time, you adapt so well that, returning to your former world, you're no longer adapted to it! (Indeed, you are probably going to have to reenter that world gradually, limiting your exposure to the Sun by spending time in the cave!)

Your second dream has a quite similar motif. Here, you at first become an animal which I would associate with grace, power, speed, beauty: factors we don't associate with our "animal nature". We are too often raised to fear that nature and to subdue it when, like your Lord of the Cave, there is in fact much good to it! But to survive, the Blonde needs the Stag, and the Stag needs the Blonde. Neither alone has the skills. Oversimplifying, it is only when the animal speed and sense of smell are coupled with the Blonde's specifically human intelligence that true survival is possible. They need each other to be truly whole!Neither can do alone what both can do together.

Of course, if you are male as your response to Silmendo suggests, our blonde is an anima figure; which complicates our interpretation but, to my mind, does not change what I have said so far. (The nice[?] thing about dreams is that, like science, every answer leads to more questions.) The underlying message: beneath differences lie the potential for unity.