Nihydron

From Memory Alpha, the free Star Trek reference

In one possible timeline, the Nihydron are a space-faring species native to a region of space near the Krenim Imperium. In 2374, three Nihydron warships joined the USS Voyager in its attack on the Krenim weapon ship. B'Elanna Torres and Harry Kim were assigned to work with the Nihydron to implement temporal shielding aboard their ships. (VOY: "Year of Hell, Part II")

The current state of the Nihydron Empire is unknown, after the temporal weapon ship was erased from time, undoing all the damage it had done.

The Species 10026 ships shown in "Dark Frontier" are identical to the Nihydron ships shown in "Year of Hell", suggesting that these two species are one in the same.