I have done Diphenhydromine many a time and each and every time, spiders were present within the hallucination onslaught. I have to warn you all to avoid Diphen, as I really don't believe its healthy for the body, mind, or spirit. I believe the reason I saw spiders is 1. Because my trip mentors had told me that I would certainly see spiders.. So, I am guessing that I expected to see them, therefore I did see them. 2. I am actively petrified of spiders and that is an integral piece of me. If I know that I am afraid of spiders, then my mind/subconscious mind will probably think about spiders once it notices that it is creating delusion hallucination in the plane of reality. I believe these two factors play a huge roll.
Story Time- A friend of mine tried taking Benadryl to achieve a hallucinogenic high back in the 90s. The trip I am about to speak of was his second Benadryl trip. He took the pills in the safety of his own home. (which, I believe is paramount to Benadryl trip safety, btw) Anyways, he took 20 or 30 of the 25mg pills and ended up witnessing his own father's crucifixion on his bedroom wall. As creepy as this may sound, it actually gets worse. Within the next month or so after experiencing this nasty "bad trip" concerning his father's crucifixion, something terrible happened. My friend's father actually committed suicide and left this earth after my friend's trip... Which, I am sure has unfortunately scarred my friend for life. These are the risks you take when using drugs of this nature.
Myself, I have also had some terrifying Benadryl trips. I once truly believed that I was being tracked down by murderous skeleton head hunters. I can remember asking my friends if I was going to die, over and over again. At the time, I really thought that I was going to either be killed by skeleton head hunters, or Overdose and die from the Benadryl itself. Very scary stuff. I also once tripped that I had walked into the woods. I had to pee very badly, and so I went into the little bathroom pavilion within the camp I was staying overnight at. I went for an enclosed toilette, rather than using a urinal. I had finished my duty, and, trying to be as sanitary as possible, I washed my hands after flushing the toilette. Here is where things got very strange... Upon walking out of the bathroom pavilion, and closing the door behind myself, I met one of my girl friends. She had apparently walked out to the pavilion with me to watch over me. Well, she seemed very dumbfounded at the sight of me. I asked her what had made her look so concerned and confused, and, if she had come out to use the bathroom as well. She simply replied "Umm... Xxxx, There is... no bathroom pavilion" I casually looked behind myself and saw that the entire bathroom pavilion had vanished. I had hallucinated the entire experience. This was EXTREMELY hard for me to comprehend at the time... And completely insane to think about sober. I sometimes wonder if I had ever actually left that trip. This entire life of mine may be a Benadryl trip as my comatose body lay in the hospital bed I had been brought to unconscious in an ambulance that night... F*ck that. haha.
End.