R is for... Rassmussen

A scientist encountered by the Doctor and Clara Oswald on the Le Verrier space station, which was in orbit around Neptune. In the 38th Century, the human race had sought to maximise productivity by reducing the need for sleep. This was still essential for physical and mental health, but technology had been developed to compress it into a matter of minutes rather than hours. 

Professor Gagan Rassmussen was the inventor of the Morpheus Pod, which rewired the human brain via a carrier wave, allowing its user to achieve a month's worth of rest in only five minutes.

An unfortunate side effect of his improvements to the system was a build-up of rheum in the eye, which gained sentience through the carrier wave. The pod users were then consumed by the resulting organisms, known as Sandmen. Rassmussen himself was a victim, but the Sandman which devoured him was able to take on his likeness.

He then manipulated the rescue party which was sent from Neptune to find out why contact had been lost with the station, creating a seemingly plausible scenario for why he had survived. His plan was to beam the Morpheus carrier wave out across the Solar System to infect everyone and so create more of his kind.

This would be achieved through people viewing the footage from the station, with the carrier wave hidden within the transmission. This was why his contrived narrative had to be exciting and interesting to watch.

The Sandman Rassmussen could not hold his form once the station's gravity shields were destroyed, and he crumbled to dust.

Played by Reece Shearsmith. Appearances: Sleep No More (2015)

• Mark Gatiss wrote the part of Rassmussen especially for his fellow League of Gentlemen star Shearsmith. Gatiss had already featured in the series, twice, as well as writing for it, whilst the third of the Gentlemen - Steve Pemberton - had guest starred in Silence in the Library / Forest of the Dead.
• In 2013, Shearsmith portrayed Patrick Troughton in An Adventure in Space and Time, which was written by Gatiss.
• One other Doctor Who connection - again through Gatiss - are appearances in the P.R.O.B.E. spin-off videos, which featured Caroline John as Liz Shaw, and Auton, all produced by Bill Baggs.