The Green is a parasitical organisim. Very little is known about it, but it is encountered in all games in The Green Series, hence the series' name.
- In Lifeline, Taylor is spoken to by The Green while inside the peak
- In Lifeline: Flatline, Wynn is able to speak to/understand The Green inside them
- In Lifeline, The Green has inhabited all of Taylor's shipmates except for the captain
- In Lifeline: Silent Night, The Green has inhabited two marines
- In Lifeline: Flatline, the Green has inhabited Wynn, but in a different way from the other. See Wynn's page for more info
- In Lifeline: Flatline, several animals and humans are inhabited by The Green. Most notably, Samson and Delilah.