Well, I know already that for golden pearls, it's a rare drop from pearls, and treant polymorphs, I THINK that you get the treant polymorphs from archivest, i saw some polymorphs, but i never payed enough attention to what kinds of polymorphs. so anyways, good luck! =] -Nicholas RubyShard, level 55 pyromancer at the moment
I got the Polymorph cards from the Archivist. You can get a Transmute Golden Pearl recipe from the recipe vendor in Base Camp. I got pearls from the Portico. You can find guides that show their locations on fansites such as wizard101central.com.
If the Archivist won't sell you the Polymorphs because you aren't high enough level, there is a recipe available to craft them. You have to have access to the Floating Land, and then look for the Water Mole on the Dock. He sells the treasure card recipes.