Baleful Polymorph is supposed to be countered by one of three spells: Greater Dispelling, Greater Restoration, and Remove Curse. J'qarr turned someone into a chicken as a prank, only for the cleric with him to discover that Remove Curse wasn't removing the curse. Fortunately, Brimstone fixed it.
Afterward, Brim took me to an OOC area to repeat the experiment. After a brief moment spent as a toad, we confirmed that Remove Curse no longer works on this spell as intended. To be safe, someone should try Greater Restoration and Greater Dispelling on it as well.