Erroneously named* and similar in many ways, these two ancient subterranean species are often referred to as “cousins”, so the guide will treat them as one. The Silurians having once ruled the planet with their Sea Devil relations acting as the foot soldiers (presumably to keep dinosaurs in check…
Reptilian humanoid creatures with ancient origins and had the run of the place long before the humans appeared on the surface, these usually peaceful creatures are only really inclined to attack in self defence. It’s just that their idea of self defence appears to be creeping onto sea forts and murdering defenceless crewmen one by one. Or creating a remote control cyborg sea dragon to attack undersea bases.
The pattern of their appearances are clear – they are sleeping or hibernating, and are woken up by the activity of the people up above. Like a grumpy tenant in a block of flats, but one that resents being suddenly awake so much that they go on a bit of a violent spree. So far, they’ve been woken by nuclear research plants, the British Navy adapting a sea fort into a SONAR testing station, the presence of a Sea Base on the ocean floor and a whacking great drill almost caving in their homes – but not, strangely, by their alarm clocks…
Sea Devils and Silurians can be easily told apart in a similar way to African and Indian elephants: the Sea Devils are the ones with large ears… but also in their weaponry: Sea Devils have to carry sonic guns, while Silurians have enough dangerous bits of the body to control a large crowd. In some cases, it is their third eye at the top of their head which emits rays and does the damage – and later on they possessed a flicky forked tongue which injects poison into their target.
Defeating them has always proved difficult – as they use their well-developed intellect to their advantage. But the fall back option of blowing them up did the trick on their first two appearances. But on the last two occasions, the Fifth Doctor resorted to gassing the creatures (having already killed the Myrka with a sort of portable sunbed) and when the Eleventh Doctor met them Marvin out of off of the Hitchhiker’s Guide decided to gas his own rebellious subjects…
* Just to prove I do sometimes pay attention to my own blather, I did point this out in series 2, episode 12 of the Ood Cast.
First Appearance: The Silurians (1970)/ The Sea Devils (1972)
Most unprepared appearance: Warriors of the Deep (1984)
Weaknesses: Pretty much as in human life – poisonous gas and bombs. Oh, and as their third eye can also act as a telepathic link, keeping secrets is a nightmare.