Ruby Thursday, AKA Thursday Rubinstein is a villain in the Marvel Universe, and an enemy towards both, Spider-Man and the Defenders.
Not much is known about Ruby Thursday’s origin. Her real name is Thursday Rubinstein. Ruby’s head was somehow replaced with a red globe of organic circuitry with a vast array of unusual powers. She joined The Headmen in the middle of their very first confrontation with the Defenders and the alien known as Nebulon. She's often used by Chondu by means of transportation.