A scopolamander (also spelled skopolamander) was a type of small animal lifeform known to live on the planet Mars, noted for its ability to run quite fast. (TOS - Star Trek 3 novelization: Mirror, Mirror)

In 2269, during the battle between Spock and Spock One on Organia, Captain James T. Kirk (due to the effects of the thought-shield) saw the drowned bodies of a wide variety of small animals, including skopolamanders. (TOS novel: Spock Must Die!)

Since conventional knowledge has found no native life on Mars, it could be assumed that this was an alien animal that took residence on Mars during a period of colonization.