* AlternateCharacterInterpretation: The alien species which sent the message with the information to create Sil. Was it all an evil plan to exterminate the human population over the Earth and replace it with Sil's offspring as it looks, or it was a genuinely friendly attempt to share biotechnology which got screwed because Finch and company couldn't handle it the right way?
* BestKnownForTheFanservice: The ''Species'' films are mainly known for one thing: Natasha Hensridge taking her clothes off a lot.
* EvilIsSexy
* FoeYay: One sided, due to Sil's and Eve's natural instinct to mate, she seems to develop a minor attraction to Preston. However Preston sees them both as a monster that has to be destroyed.
* HilariousInHindsight: One of Sil's victims in the first was named John F. Carey. The 2004 Presidential candidate was John F. ''Kerry'', who was a well-known senator at the time of the movie.
* NightmareFuel: Many of the deaths are brutal (such as Sil ripping the spine of a woman), the alien transformations are as disgusting as the ones from ''Alien'', and even [[http://www.youtube.com/watch?v=x4aydQSu7-E the first movie's soundtrack]] contributes to a creepy atmosphere.
* ParanoiaFuel: See FanDisservice.
* {{Sequelitis}}: The first film is generally regarded as most popular due the the various reasons mentioned on the main page. The second tries to make a bigger spectacle which worked for some and not for others.
** The third and fourth films came about by the two picture deal with Syfy. The third pretty much comes off more like you would expect a scifi tv show to. Which to some was a far cry from the first two, while others appreciated it. While the director of the third had plans for the fourth it instead tried to examine a different WhatHappenedToTheMouse and most would probably agree made a film that made the second and third less bothersome.
* SpecialEffectFailure: The aliens prosthetics in ''Species III'' are vastly inferior to what was seen in the two previous films. ''The Awakening'' has similarly bad effects, but for the most part it does a better job of working around them.
** In the first film, the "mist" in the woods outside the hot tub guy's house is patchy, obviously from a smoke machine. Also the ConspicuousCGI in the final scenes (which H.R. Giger complained about, saying that unlike the animatronics they weren't worthy translations of his design).
** Take a real close look at the monster effects at the end of "Species II". The constant strobes are there to make you miss how terrible and awkward they look.
* StrawmanHasAPoint: Xavier says they made her female assuming she'd be more docile, which is [[YouNeedToGetLaid seen as funny]] by Preston and [[CriticalResearchFailure it's actually untrue]] as female members in Earthly predatory species tend to be more aggressive than males. But by doing so they actually may have bought themselves more time, considering a female only can have one partner and reproduce more or less one by one while a male can have multiple ones at once and impregnate all of them.
** And considering what we see of the male hybrid in the first sequel, he turns out to be pretty close to being entirely accurate.
* VisualEffectsOfAwesome: There's no denying ''Species II'' had some pretty awesome scenes.