Apex Predator is a United Colonies mission in Starfield.
Your objective is to help Percival collect samples.
Here’s a walkthrough and guide of Apex Predator in Starfield.
To begin the mission, go to Mars and talk to Percival after you’ve completed the United Colonies mission-line.
You can then recruit Hadrian as part of your crew.
Collect samples on Muphrid V-B
Next, go to Muphrid V-B to find samples. Land at the Natural Archways.
You can either kill the aliens to collect their samples or you can do it non-lethally.
One easy way is to use the Void Form power that makes you invisible. It allows you to harvest sample from them while you’re invisible.
Deliver the samples
Go back to the TMD headquarters to deliver the samples to the Xenobiologist waiting outside.
The mission ends here. You’ll earn 3000 credits.
You can probably do more sample-collection missions just by talking to Percival again.