**Disclaimer**
The idea for these creatures came from a Tales of Terror story (http://www.talesofterror.net/tale0219-freighter.html) as was the first plot option. I simply expanded upon the idea of the spiders. I am sorry that I forgot to point this out when first submitted.

Full Description
Wood spiders are best described as 'apparently harmless', unfortunately, this is not the case. They are about as large as a common house spiders and are simply adorned with a quiet, woody pattern on their backs. Though they are there, the tiny fangs of wood spiders are so small that it is nearly impossible to see them without outside help (i.e. magnifying glass, magic).

These spiders, unlike their more normal cousins, scuttle sideways like tiny crabs, but cling to and climb upon surfaces just as well.

Additional Information
Although they appear harmless enough, wood spiders are actually very deadly. Their venom, though not fatal in itself, causes extreme paranoia in the affected creature. This usually causes their victim to shun contact with others, to the point of starving themselves, go on a bloody rampage to kill those responsible (for what we're not sure), or both, one after the other.

Wood spiders are named such because they lived inside hollow spaces in trees. No one has ever seen spider create these spaces so most people think that they simply steal them from other creatures such as squirrels. Wood spiders live inside their trees in close-knit nests of between ten- and fifty-thousand spiders and spiderlings.

The natural prey of wood spiders are insects that they catch in their distinctively shaped webs. Their webs are constructed like small domes that stand up from the trees that they inhabit.

Plot Options
-A strangely silent ship ails into port one day. But when it is searched, only one survivor is found, a babbling, blood-drenched sailor. All the others on the ship have been slaughtered. The ship was carrying a supply of logs from another port to the south. The logs contained a nest of wood spiders which got out of the hold and started to bite crew members. The affected began to kill until only one was left.

-An infamous assassins guild uses these spiders on their marks. Even if they don't kill themselves, they'll usually be pronounced insane and locked away forever.

-Small town after small town has fallen to the bite of wood spiders. Luckily, right behind the plague has come a shabbily dressed man selling antidotes to the venom.

?