I'm usually a fan of spiders as they eat flies and don't bother you (normally Jimmer lol)
A few years ago i was spraying some car parts in my cellar and had left them to dry. I came back a the next day and lifted up one of the parts and found one of these below:
It stood up on its back 4 legs trying to make itself seem big, and then i saw its fangs!!!
its one of only 2 spiders in the UK that bites humans but it isn't poisonous.