Upon Death, the Dwarf Reverts to its Natural Form…
To identify this creature, make a DC 15 Intelligence (Nature) check. Success reveals that [the creature is a doppelganger. It can assume the form of another creature as tall or smaller than itself].
If the result of your check is 20 or higher, [you also know that this creature is capable of reading the surface thoughts of other creatures].
If the result of your check is 25 or higher, [you may learn all information from the doppelganger’s stat block].