The Macra were first seen in The Moonbase (Classic Series) with a brief appearance of their claw, though their full bodies weren’t seen until The Macra Terror (Classic Series). The Macra are giant crustacean race, resembling over large crabs, that fed on unclean gas as well as humans to whom the gas was also poisonous to. The Sapient Species seen in The Moonbase and The Macra Terror were larger than humans, able to hold one in one of their large claws, with large claws, including a smaller set beneath the mouth, large eyestalks and a stocky build. The Predator Species seen in Gridlock (Series 3 : Episode 3) were far larger than the Sapient Species, with claws so big they could hold one of the New Earth cars. The body was smaller in proportion to the claws with six spindly legs and glowing eyestalks.

Predator Species Macra seen in Gridlock

The Predator Species of Macra hunted by movement and shown to have no sign of intelligent, alongside loud, terrifying and distinctive roars. The Doctor described the Macra’s as the “scourge of this galaxy” who were an ancient race with a large empire but had devolved into feral creatures. In The Macra Terror, an a planet colonised by humans, the Macra used the humans as slaves to mine for gas that the Macra need to live on. The Second Doctor started an uprising against the Macra and exploded their control room killing the Macra leader and seemingly dooming the Macra on the planet to die. In Gridlock, the Macra were creatures kept in the New New York Zoo but escaped when the power went down and moved into the motorway network of New New York, feeding on the poisonous fumes in the depths of the motorway and any meat (humans, cat people, etc) that strayed into the Fast Lane. The Tenth Doctor seemingly defeated the Macra by opening the roof of the motorway network with the assistance of the Face of Boe, allowing the cars to escape, depriving the Macra of food and gases.

Sapient Species Macra seen in The Macra Terror