An arachnid order known as the Solifugae, characterized by its large chelicerae (mouthparts). Camel spiders also feature what looks like 5-pairs of legs, though the the first pair are pedipalps instead of legs and are used as a set of feelers. The first pair of real legs are also used as feelers and are typically smaller and thinner than the rear 3 pairs of legs used for walking.
Note that the Solifugae and Araneae (common spiders) are from different orders.