Cyberman android
The Cyberman androids were tall, black androids created by the Cybermen when they planned Earth's destruction in 2526.
The Cybermen had hidden a bomb within a cave system on Earth, planning to detonate it to destroy the planet. When an expedition team was studying the caves, the androids were created to guard the hatch which held the bomb.
The androids made a distinctive whine and were not detectable on scanners. Their right hands had weapons embedded in them that could turn a human into a pile of burnt flesh. They were fitted with monitoring so that the Cybermen could recieve the images and the Cyber-Leader was also able to communicate with them.
The androids were impervious to energy weapons and could only be destroyed by concentrated fire.
They were programmed for survival and if they were damaged they wouldn't take unnescessary risks. However, this allowed the Doctor to confuse them by having Lieutenant Scott's men fire at the hatch. This confused the androids and allowed the soldiers to destroy them. (DW: Earthshock)