These parasitic aliens are deadlier than Star Trek: Strange New World's version of the Gorn
The finale of the first season of Star Trek: The Next Generation, "Conspiracy," introduced parasitic aliens that infected their hosts, with Lt. Remmick being one of the unlucky recipients. We didn't know the full extent of the damage these aliens could do until Star Trek Defiant #12 brought them back.
Warning: contains spoilers for Star Trek: Defiant #12!
According to Screenrant, the parasites are back in Star Trek: Defiant #12, and they are deadlier than ever...even more so than we realized as this was never a story that had a resolution. We never knew what happened to those aliens, but the comic book series is telling the rest of their story. And, according to an autopsy on Lt. Remmick done by Dr. Beverly Crusher, the parasite has not only destroyed much of Remmick's body, but they left him in such excruciating pain that it likely drove him mad.
While the Gorn are terrifying opponents that the crew of Star Trek: Strange New Worlds will face off with again in season three, at least those aliens can be seen. The parasitic aliens can sneak up on a person, and before they know it, they're infected. That makes them much deadlier and fearsome, and with Star Trek: Defiant #12 returning them to the forefront, it makes a good argument for bringing them back onscreen.
While the Federation will be fighting these creatures in the comic, fighting them onscreen would be terrifying as they weren't defeated in The Next Generation's "Conspiracy." So what exactly will it take to defeat them? Is it even a possibility? How do you fight something you can't see? I think that is a "worst nightmare" scenario and worthy of further exploration in the Star Trek universe.