I had a nightmare about a spider yesterday.
This is what I found on the internet about it.
'Spiders are also a very old form of life,' says Dr Lukeman. 'One of the things they represent in dreams is something very primitive and basic - something rooted in the depth of our being, such as our mother. For someone who comes from a family where the mother was unloving , a spider can be a perfect dream symbol. The evil mother becomes an evil spider.'
Article Source:
http://www.dailymail.co.uk/health/article-52177/Five-common-nightmares--mean.html