What is the singular possessive nouns for dog rexdar woman and baby?

The possessive form of the singular noun dog is dog's.

example: The dog's name is Santa's Little Helper.

The possessive form of the singular noun woman is woman's.

example: The woman's name is Eleanor Abernathy.

The possessive form of the singular noun baby is baby's.

example: The baby's name is Maggie.

There is no noun in English spelled 'rexdar'.