A polymorph gains the abilities of what it transforms into, they change their form freely and are considered a dangerous plague on any realm. Not only do they get abilities, but also their memories and social interactions with other people.
Shapeshifting takes time to learn and control
Polymorphs can do it freely and with no need to practice, they do not live long so they started to die out and try to make stronger heritage, until they managed to have Red after so much time and so many who died of them.
What’s the difference between a polymorpher and a shapeshifter or it’s kust the same thing but fancy name?
Nice Food 