Invasive plant species
Anything that behaves like an invasive species (such as weeds) but also noticeably changing the area as it spreads, overwhelming native forms of life.
Alternate name: Alien weed
The first video game about Invasive plant species was released on October 16, 2003.
Cases where this exists only in fiction should not be included, nor cases of invasive animal species (especially sentient beings).
Notable in-fiction only cases:
* C&C Tiberium series
* Dead Space series
* System Shock 2