Mix poultry seasoning, salt, and pepper together in a bowl. Rub on turkey legs. Refrigerate, 8 hours to overnight.
Dissolve bouillon cube in water in a bowl. Pour into the slow cooker.
Form aluminum foil into a coil shape, at least 1 inch in height. Line it to the bottom of slow cooker. Rest the turkey legs on the aluminum foil, above the liquid.
Cook on Low until meat starts to fall apart, about 7 1/2 hours.
