The first card to bear the creature type was Ekundu Cyclops in Mirage. The subtype Cyclops was obsoleted in Sixth Edition but reinstated in the Grand Creature Type Update. Inbetween cards like Tar Pit Warrior, Hulking Cyclops and Bloodshot Cyclops had the subtype Giant. Cyclopses appear in red, black and green. They are known to exist on Alara, Dominaria, Ravnica and especially on the Greek-inspired Theros.
An Eye Gouge is lethal to cyclopses.