I had to look it up but I guess Polymorph spells can be dispelled.
Doesn't mention it, so i'm guessing you can: https://www.d20srd.org/srd/spells/polymorph.htmThis info was in a 5e forum. Does anyone know if in past editions if Polymorph could not be dispelled?
more importantly is the way Dispel Magic is written:
Some spells, as detailed in their descriptions, can’t be defeated by dispel magic.