Sectoid Commander: More advanced and deadlier than their lesser Sectoid counterparts, the Sectoid Commander is a variant encountered in XCOM: Enemy Unknown. Additionally, in XCOM 2, Sectoid psionic abilities can be halted by flashbangs and other disorienting effects. Sectoids in XCOM: Enemy Unknown are fragile and fall easily to most attacks, while in XCOM 2 they take extra damage from melee hits. The Sectoids have appeared in every game in the XCOM series, though as of XCOM 2 their design changed and incorporated human DNA into their genetic code.
Sectoid: The Sectoid is the most basic of the alien units in the XCOM series, featuring a design not unlike the stereotypical alien. Finally, the aliens present in the tactical third-person squad-based shooter, The Bureau: XCOM Declassified, will be covered to finish it off. From there, XCOM 2 will be covered, with the Chimera Squad variants mixed in as already explained. Now that the bases have been covered, the first set of aliens will come from XCOM: Enemy Unknown and almost all will make a return in later games, especially Sectoids and Mutons. Related: XCOM: Chimera Squad - How to Earn Intel Sources (& What They’re For) Lastly, the aliens are grouped based on their primary versions then the variants of this primary version are expanded for example, Sectoids are the primary version, while the Paladins in Chimera Squad are a Sectoid variant. Human enemies, which are the dominant force in XCOM: Chimera Squad will not be mentioned in this list, only the aliens and alien hybrids will be included. With each installment in the series, the enemies change and often become more or less of a nuisance than they were in previous installments. Starting with XCOM: Enemy Within and going to the newest release, XCOM: Chimera Squad, this article will provide a list of every alien variant in the XCOM series as well as cover the best tactics to use against them. The aliens in the XCOM series vary in difficulty and danger, ranging from cannon fodder to apocalyptic threats, with the Extraterrestrial Combat Unit, XCOM, at the center of the war. The XCOM series is a turn-based strategy game of humans versus an alien invasion.