From publisher blurb:
A highly territorial relative of the Giant Spider and Giant Scorpion, the Giant Whip-Spider, (or Amblypygus), is both more and less threatening than its cousins. While it lacks a venomous bite or sting, it’s as fast as a horse and large enough to consider most creatures smaller than itself as potential prey.
Six of the arachnid’s legs are long, slender things used for locomotion - sometimes forward, but more often sideways like a crab. Two, however, are adapted into long whip-like antennae which are used to feel out environments and locate suitable prey - and as a side effect of the creature’s immense size, to literally whip soft-skinned enemies into submission. Their massive pedipalps are used much like a Mantis’ forelimbs - to grab, pierce, and crush enemies while the spider eats them.
For such territorial creatures, they can be oddly social - mothers of some broods have been observed communicating with their young using their feelers. Rumor has it that some tribes of Kobolds have managed to tame Giant Amblypygi using whips to communicate simple commands.