Some fanfictions might show the 'Facehugger' concept being used as a form of biological warfare within the Star Trek TNG universe. A rogue group could be using these facehugger - like creatures to target key Federation personnel or planets. The Starfleet crew would then have to find a way to stop the spread and counter the threat. This could involve developing new medical countermeasures or using advanced technology to neutralize the creatures. It also might lead to some interesting ethical debates within the crew about how far they can go to stop the threat without sacrificing their values.
Another way it's incorporated is by creating a crossover situation. Maybe a wormhole or some other space - time anomaly brings the 'Facehugger' from another universe (like the Alien franchise) into the Star Trek TNG universe. This would cause chaos as the Enterprise crew tries to figure out what this strange new creature is and how to deal with it. They might initially misinterpret its abilities and nature, leading to some tense situations on the ship before they finally understand how to combat it.