The common house centipede. They are very common in my house, I have a lot of them. But that's ok. Because of them, I don't have many ants, silverfish or roaches--in fact, I have none. That's because these little guys are voracious eaters of the other little guys. And may it always be that way.
They are completely harmless to humans. You can pick them up with no fear of getting stung. In fact, they play dead. They are non-aggressive towards humans unless you end up like the incredible shrinking man, in which case you'll find them pretty aggressive and pretty damn fast.
A very primal looking creature, centipedes are like living fossils walking the earth since antediluvian times.