The largest that the get is about 5 inches, and aren't even poisenous.
So chill out, wuss.
This animal can grow up to approximately 12-15 cm (5-6 in).
They have two large, hooked pincers which assist in catching and masticating their prey. They are also able to easily escape many enclosures, due to their ability to run up glass and bite through most wire mesh. If one escapes, there is really no good course of action. It can run up to 10 mph over short distances, and is very maneuverable. It may also pursue you if it senses a threat.
Although it is not venomous, Its sharp fangs tear a disproportionately large bite which is prone to infection. They eat approximately their body mass in food every two days, so keep them full, and they will be less prone to escape and chew your family.
Jim - "Why the hell did you get one of them? The only good thing about them is they only live 18 months!"
Bill - "No, they're cuddl-" (Screams as it masticates his thumb)