Scorpions

Scorpions are arachnids, which means they have eight legs. However, they are not spiders. They have pincer claws on their forward legs and a tail stinger that can inject a powerful venom into its prey.

In fiction
The Marvel Comics super-villain, MacDonald Gargan assumed a costumed identity and began calling himself the Scorpion. He became a reccurring foe of Spider-Man.

On the Showtime TV series Penny Dreadful, Ethan Chandler found the symbol of the scorpion on the floor of Vanessa Ives' bedroom. When asked about it, she explained about the time she met the witch, Joan Clayton. Joan had called her a scorpion and used the animal as an analog to Vanessa using her psychic powers to learn more about Clayton. After Clayton was burned as a witch, Vanessa cut her thumb open and drew the image of a scorpion on a grave marker in her own blood.