Arachnid

Spiders were a type of arachnid found on Earth.

According to Nyssa, arachnids knew how to build webs instinctively. (AUDIO: Alien Heart)

Glomi IV was a planet home to six-armed arachnids. (PROSE: Death and Diplomacy)

Scorpions were arachnids. (PROSE: The Ruby's Curse)