Due to the lack of markings, I disagree with Parsons spider, but it is a close relative (Family Gnaphosidae). They're all harmless.

I'm guessing it's a member of the genus Zelotes. Compare:

http://bugguide.net/node/view/253492/bgp...

Spiders need water like any animal, and the bathroom is about the only place in the house with standing water. This fella might have been searching for water and fell in and gotten stuck.

It's a Parson Spider, Herpyllus eccleasiasticus, one of the wandering hunters that eat pesky bugs in your house. It's harmless to people and their pets, unless you have a cockroach as a pet.

http://bugguide.net/node/view/2041

I found THIS spider in my toilet this morning and this is the 3rd time it's happened! What type is it and why do they always go to my toilet!? Help please