As expected from the Space Aliens, like all retro sci-fi extraterrestrial life, little is known about these orange plastic lifeforms, save the facts that their actions are psionically dictated by the Overlord, originate from Plastic Space, possess technology advanced beyond human plastic levels, such as their Saucers - and they wish to conquer the entire known universe... by eliminating their hated opposition, the Galactic Army.
As Tina Tomorrow secures an alliance with Sarge and therefore the Green Nation, the aliens form an alliance with the Tan Republic and join in the quest for domination by providing a whole new armada of lethal creatures, deadly new weapons and other nasty things to make Sarge's life miserable.
The earliest stage of Alien evolution and therefore the weakest, wormlike lifeforms capable only of spitting acid. In two words: target practice.
Another stage of evolution before the Drone, but its close combat attack is limited in range and must come in swarms for effectiveness.
The grunt trooper of the Alien Army, armed with Blasters that can blast holes on enemy plastic troopers - literally.
A larger version of the Drone, usually in command of Alien strike groups and armed with stronger Blasters that can eliminate almost anything.
Octopus-like mutants with a single oversized eyeball capable of firing a painful death ray - a few well-placed hits and you're dead plastic.
The ultimate Alien in charge of the invasion, controlling the actions of the whole Alien race. Its immediate destruction is paramount, but approach at your own risk. it launches a fiery explosive motor that releases alien spiders also after death a horde of alien larval are released from a area lower on the board and if they reach the main section they can recreate the alien overlord.