The freaking Megarachne!
This thing has 8 massive flipping limbs. It has a red glowing creepy widow-spider symbol. Megarachne has extreme amounts of armor, unless you attack it's widow spider engravement. This is found in Marshes, Mountains, and the Desert if that is added. The Megarachne deals insane amounts of damage. The only thing wrong about the Megarachne is it's very slow. Also, it jumps very high, higher than anything else. It deals little amounts of torpor, but it still can really be a bugger in battle. As a mount, it can swim very swiftly. There is a normal saddle, and a Launcher Saddle. The Launcher Saddle is literally a saddle, where the Megarachne launches you super high in the air! (Achieved at lvl 85)