Tajniak (; died 1984) was a Polish Catholic priest Jerzy Popieà Âuszko's dog.
While Father Jerzy was attacked and received death threats including by phone and letters, students in Warsaw gifted Father Jerzy a black puppy to cheer him up. Therefore, the puppy was named "Tajniak."
Tajniak was a black puppy who was named as Tajny (), but it was called Tajniak instead, or "secret agent." The reason why the puppy was called Tajniak was that it "followed [Father Jerzy] everywhere." In relationship to Tajniak, Father Jerzy was a "father" to the puppy. However, the puppy did not live long because Tajniak broke off its leash and was run over by a Nysa car, which the cop did not intervene.