Multiple realities(covers information from several alternate timelines)
The Zahl were a technologically advanced and generally benevolent humanoid species native to the Delta Quadrant.
The Borg had encountered the Zahl and evidently assimilated some of them as Seven of Nine reported their resistance quotient to be "quite low".
In one possible timeline a generation prior to 2374, the Zahl defeated the Krenim Imperium. They disbanded the Krenim fleet and retook the territories they had annexed.
In 2374, two Zahl starships greeted the USS Voyager upon its arrival in their space. During the meeting, the entire Zahl civilization was erased from history by Annorax's weapon ship. The erasure of the Zahl achieved an unprecedented 98% Krenim restoration, although the Krenim colony on Kyana Prime was not restored. (VOY: "Year of Hell")'
The Zahl ambassador was played by Rick Fitts.
It is unknown what became of the Zahl after the timeline was returned to normal.
- No Zahl characters were ever assigned names in canon productions.
Star Trek Online's Delta Rising expansion reveals that in the restored timeline, the Zahl were allied with the Krenim Imperium until the Krenim were defeated by the resurgent Vaadwaur.