10 Star Trek Villains Who MUST Get Their Revenge
3. The Devidians
The Devidians were discovered, almost simultaneously, in both the 24th Century and the 19th Century - going by Earth's calendar. They operated from a base on Devidia II, travelling through space and time to hunt for food in San Francisco of the past. As often happens, an Enterprise crew travelled through time and put a stop to their shenanigans.
That said, and accepting that the Devidia II base was destroyed by a volley of photon torpedos, it seems highly unlikely that the Devidian people would simply stop trying to find their snacks on the homeworlds of their foes. Perhaps they really did have only one base (which is just so foolish from a strategic standpoint, so we'll assume that isn't the case) but they can't have been the only ones engaging in this food run.
While Earth may not have panned out, they certainly found success in time travel. With that, it stands to reason that they would try again, and again, as many times as it took to find the one place and time that suited them best. Though the female Devidian seemingly died, she did get a good look at Picard and Guinan before she went and we have no idea what death looks like in Devidian anatomy. Perhaps her memories survived, transferring through the Devidian people, allowing them to begin concocting years of revenge and torture.
Or maybe she's worm food. Either way, what the heck are the rest of them up to?