- Hey, It's That Guy!: Marg Helgenberger, whom fans of CSI may recognize as stripper-turned-investigator Catherine Willows, plays the head of the research team in the first three movies.
- Hey, It's That Voice!: Frank Welker, who you might also know as Megatron provided Sil's noises. Sort of kills some of the hotness, huh?
- Old Shame: Michael Madsen doesn't have good things to say about Species II.
- Playing Against Type: Michael Madsen, normally a villain, plays The Hero. With one particular scene establishing him as a Kindhearted Cat Lover.