Hi, welcome to the forum, you are going through visual hallucinations which seen due to neuroophthalmologic dysfunction resulting from a wide variety of underlying etiologies. This condition can overlap with visual illusions which include distortions of size (micropsia or macropsia), shape (metamorphopsia), and color (dyschromatopsia).
The type of hallucinations you are experiencing is known as Complex or formed hallucinations as you see things with details like animals, people etc. In such cases it is very important to note any other conditions like eye problems, stress, confusion, memory loss, alcohol, drug, and medication history is also important.
Conditions which can present with such symptoms are Migraine (aura manifests as visual hallucination), Seizures, Alcohol and drug use, psychiatric illness and metabolic encephalopathy.
You need to undergo polysomnyography (PSG) to rule out sleep disorder, EEG to rule out any epileptic foci, and also psychiatric evaluation which will help to rule out any factor.
I suggest you to sleep with lights on, good sleep hygiene, long acting sedatives against prescription will help you maintain sleep, keep away from any triggering factor (smell, food etc. need to be identified.), share your inner feelings with family and friends, hot and cold water bath will help you to alleviate condition.
I suggest you to consult neurophysician/psychiatrist for further evaluation. Take care and regards.
Are you on any meds that can cause this? I have a friend who sees scary things when she wakes up during the night. She was told it is her med, but the med is otherwise effective so the doc told her to keep a flashlight under her pillow, and when she wakes up seeing something to shine the light on it and it will disappear. It works!
Another friend was seeing giant spiders on the wall. She was tested for sleep apnea, and was told the images were part of her oxygen dropping real low with the sleep apnea and causing hallucinations.
I have only had one period of seeing things at night that weren't there. Mine was due to a medication. I was very much awake, and seeing small blinking lights around the globe of my ceiling light. I was convinced the person in the apartment above me had somehow bugged my bedroom and was watching me. Wanting to mark the spots, I got up, taped a felt tip pen to the end of the broomstick, stood in my bed, and put an "X" in the places where I saw the blinking lights. The next day my family came over and dismantled the light fixture, but there was nothing there and a concrete barrier was between the two apartments.
See your doctor and ask them to figure out why you are having these episodes.