Invasion!
The "Invasion!" event in Stellaris — flavor, choices, and how to trigger it with the event console command.
Invasion!

Planet eventMean time: 240 months
The subterranean aliens on … have marshaled enough forces in their underground empire to launch another invasion of the surface! Once again their frenzied armies are pouring out of freshly dug tunnels to challenge us.
The command below will trigger the "Invasion!" event in Stellaris:
Player choices
When this event fires, you can choose between the following option:
- We need to drive them back!
- Hostile armies are attacking our colony on …!
Firing conditions
Show raw conditions
has_planet_flag = seismic_disturbance_war
pop_amount > 0