Tank

Tanks are a type of offensive unit. They can fire damaging projectiles at enemies.

In Planet X1
There are only two tanks and they cannot be recreated. Tanks can fire at alien spiders. Taking fire from spiders will cause the tank to be destroyed. When they drive into lava they are immediately destroyed.

In Planet X2
Tanks can be built at factories. They can fire at Protoids to damage them or damage the terrain or buildings. They also can self-destruct to cause a big explosion, which is useful if it is determined that the tank will be unable to survive anyway.