The cat chased by the dog carrying the mouse to be revenged is called Tom. The cat /chased by the dog/ carrying the mouse/ to be revenged/ is called Tom. The cat / ... / is called Tom /The cat/ subject / .. is called Tom./ linking verb and subject complement The cat /chased by the dog/ ... / is called Tom /chased by the dog/ participial phrase modifying "cat" The cat /chased by the dog/ carrying the mouse/ ... / is called Tom. /carrying the mouse/ participial phrase modifying dog The cat /chased by the dog/ carrying the mouse/ to be revenged/ is called Tom. /to be revenged/ passive participial phrase modifying mouse (note - revenged is incorrect ... avenged is correct)

This is a very poor sentence. Grammar says dog - but the intended meaning is unknowable, since the control of grammar is so visibly poor.