Deep One (X-Com)

The Deep One, according to its UFOPaedia entry in X-Com: Terror From the Deep, is a biological nightmare, born from the insidious alien biological experiments. The creatures are used as Terror Units by the Gillmen and are found defending T'leth in the first phase of the T'leth attack.

The Deep One, as mentioned earlier, is a creature that is half-human and half-Aquatoid, bred by said Aquatoids to be amphibious frontline troopers. The creature has many Aquatoid features, like webbed hands and feet. Their faces are hidden behind dark masks. Overall, the Deep One has no human semblance, with the exception of their eyes. They wear ponchos that look like rags and have some sort of breathing apparatus tube attached to their face. Their skin is protected by Aqua Plastic armor, allowing them to take a decent amount of punishment before dying. Performing research on a Deep One's corpse is required to research Aqua Plastics.

During terrorist attacks on coastal sites and shipping lanes, Deep Ones tend to stay hidden in secluded corners, waiting for a careless civilian or Aquanaut to stumble into their field of vision. Then they unleash a powerful electric attack that can easily dispatch an unarmored Aquanaut or civilian. A good way to find Deep One, or any alien that is hiding somewhere, is to thouroughly sweep all corners of an area until the flashing enemy sighted box appears at the lower right coner of the screen. If you have enough time units, send it to Davy Jones' Locker. If not, get behind a wall since they have the attention span of a gnat and suffer from short term memory loss. If you can't attack or hide or call in for backup, better hope that the closest Aquanaut has a Med-Kit and that the former gets nothing worse than a serious wound or unconsciousness, and the only thing worse of course is death.