You must learn a special skill to tame plant beasts (Florafaun). It's taught by the tome, Trials of the Florafaun Hunter which drops from at least some florafaun rares in Harandar.
Ambystans are proto-axolotls. They aren't officially part of the Toad family but we've decided to include them for now, as the addition of gromits means the family includes other amphibian groups.