First one is Dragon Priestess which looks like the Dragon Prestess in Grand Alter of Dragon Communion and the other one is your standard Dragon form, looks simialr to the one in Dark Souls 3.
Dragon Presitess one can be acquired by killing Bayle the Dread. Kill the boss and revisit the presitess and you'll find Priestess heart at her location.
For the other one. Follow the route to the top side of Jagged Peak. The area looks has a "C" shape . So top protion.
Keep following the path, until you reach that jumping pad and then a spirit guy sitting on a chair. Pretty hard to miss.
Wait for him to disappear and pick up the heart.
Once you have any of them . Remove all clothes and consume the heart to obtain any of those forms