How do you get Regenerable pets specifically zolnixis without buying them off others because the others have to get them some way and I want to know how

When the Nixis were redesigned certain traits were moved from one mutation / gene to another which lead to some clashing (e.g. if the Nixi had M1 Pearl Armour and M3 Spirit Flames there would be a clash because both those traits have been moved to M2) - its those Nixis which are regenerated. You can find more information about the redesign here.

As a result of the above, its only Nixis that were in existence (and that met certain criteria) when the redesign went live that are regenerable. The only real way to get them now is to buy them from other users - hence why there's a bit of a premium price on them.

Never mind, I was too slow. :-P

Ah I see I like the regerables someone gave me one so I was curious anyways thanks for answering

They're definitely in demand because you can just about make your own Nixi! When Vorpas were revamped, some pets could even have colors redone- I made my Tank, Sapa, beautiful that way x3.
For Nixi, I've bought a number of re-gen ranging from 75K to 150K depending on the number of points.
But as someone's stated, the Nixi had to have had certain traits that were messed up for them to be re-generated, so the only way to "get" them is to buy them.