Name – Slaar
Species – Ice Warrior
Planet – Mars
Temperament – militant
Appearances – Seeds of Death

Slaar was the leader of the Martian commandos which took over the Moonbase. He tried to destroy human life on Earth by using the T-Mat system to spread the deadly, oxygen-absorbing "Seeds of Death". He was outsmarted by the Second Doctor, who caused the Martian fleet to plunge into the sun.

Slaar died when he was accidentally hit by one of his own Warriors' sonic blast