Scorpion

Scorpions, relatives of spiders, were a type of arachnid with powerful claws and a venomous sting in their tail.

The Tong of the Black Scorpion was a criminal organisation on Earth whose members all had scorpion tattoos on their hands. To avoid giving up information about their organisation they were expected to swallow a pill containing scorpion venom. (DW: The Talons of Weng-Chiang)

An intelligent race of giant scorpions formed after the extinction of Earth's dinosaurs were led by the Scorpion King, who taught them to recite Block Transfer Computations. (BFA: The Boy That Time Forgot)

Richard Lazarus was periodically mutated into a scorpion-like creature at random intervals as an unintended side-effect of his Genetic Manipulation Device. (DW: The Lazarus Experiment)