It hugged the host's face tightly, finger-like appendages locked around the host's head.
Its systems began shutting down, one by one. It could only live so long without the embryo to support it. That embryo was now the fetus now developing safe and sound within the host to which it had been delivered.
It's job was done. It loosened its grip on the host, retracting it's phallus from down the hosts throat. The seeder dropped to the muck below, and scurried away to find a dark corner in which to die, it's own directives completed to full satisfaction.
It felt no regret for what it had done, or that its short life was nearly over. It had served its purpose, and that was all that mattered to it.
It curled up in the night, its acidic pulse slowing. Another function shut down. And then another.
The seeder's pulse stopped, and it became still. It's life was over, but it's legacy had only begun.
Some ten yards away, the xenomorph fetus stirred in it's host.