Source: Drow of the Underdark
Instead of an animal, you bond with a monstrous spider.
Prerequisite: Vermin Trainer, animal companion
Benefit: You can select a monstrous spider as your animal companion. This spider gains all the benefits normally granted to animal companions.
At 1st level, you can select a Tiny, Small, or Medium monstrous spider as your spider companion. A druid of sufficiently high level can select a more powerful creature as her spider companion, applying the indicated adjustment to the druid's level (in parentheses) for the purpose of determining the spider companion's characteristics and special abilities.
|Spider||Minimum Level (Adjustment)|
Normal: Spiders are not available as animal companions.