Star Trek: 10 Disastrous USS Voyager First Contacts
4. Biomolecular Warheads First, Class Reunions Later
No sooner had Voyager reached Borg space than they encountered yet another implacable enemy in the form of extremely tall, exceptionally grumpy creatures from another dimension. It was the unlucky eternal ensign who made first contact with Species 8472 — or, rather, they made first contact with him — although Kes had been in telepathic touch for a while before that. "The weak will perish" was 8472's opening message. Not the best place to start a dialogue!
It was all Borg shenanigans and gullible foxes from there. When it came down to it, Janeway preferred to fight rather than being caught, Starfleet-issue trousers down, "tinkering with the deflector". Floating through fluidic space, Voyager used its warheads against 8472. Surely helping to develop biological weapons was also a violation of The Doctor's ethical subroutines?
Second contact didn't begin much better (they were probably expecting the Boimler types). Voyager found a group of 8472 impersonating Starfleet officers, probably as a prelude to invasion. Replicant Boothby soon calmed down, however, and an indefinite truce was called. Just how do you shake hands with an 8472? I believe their traditional greeting is a strong, sweeping hit to the chest. Ask Harry Kim! He's the expert.