The Snake Plant, or Mother-in-Law's Tongue, is one of the most recommended plants for improving air quality.
It is also known as "the bedroom plant." While most plants take away oxygen at night, this one gives off oxygen at night.
Caring for the plant: It does need to be watered occasionally but not a lot. It generally prefers drier conditions and some sun.
The plant is mildly toxic to pets as it does contain saponins; natural chemicals produced by the plant to protect it from harm. The level of toxin, however, is relatively low.