The Power Pack had costumes made of unstable molecules manufactured for them by the Kymellian smartship Friday; as the alien Kymellians had no direct contact with Earth natives prior to this, it's possible that they developed their own form of unstable molecules, as certain Kymellians naturally develop super-powers.
Unpronounceable by human tongues, the Zn'rx are known better as "Snarks" among Earth's superheroes because they were nicknamed that way by a Kymellian called Whitey, who named them after the monster in Lewis Carroll's poem "The Hunting of the Snark".