Cy-Bugs are like a virus. They don't know they're in a game. All they know is eat, kill, multiply! Without a beacon to stop them, they'll consume Sugar Rush! But do you think they'll stop there? (Fix-It Felix: Yes!) WRONG! Viruses do not stop! Once those Cy-Bugs finish off Sugar Rush, they'll invade every other game until this arcade is nothin' but a smoking husk of forgotten dreams.
~ Sergeant Calhoun to Fix-It Felix about Cy-Bugs.

A Hostile Species is an entire race of evil creatures and/or people, common in sci-fi and fantasy genres. Some later redeem themselves, and some individuals within a species may differ in their beliefs. This category has its own template infobox.

They are also difficult to defeat if, despite being naturally hostile, xenophobic, or even evil, they are capable of having children or making families; thus, killing a hostile species that is capable of reproducing naturally would still be considered an act of genocide.

Note: Add only races or species to this category. Individual villains do not count.