Question: Cerberus's parents are Echidna and who?

Context paragraphs:
Chimera (mythology): The Chimera ( or , also Chimaera ("Chimæra"); Greek: Χίμαιρα , "Chímaira" "she-goat") was, according to Greek mythology, a monstrous fire-breathing hybrid creature of Lycia in Asia Minor, composed of the parts of more than one animal.  It is usually depicted as a lion, with the head of a goat arising from its back, and a tail that might end with a snake's head, and was one of the offspring of Typhon and Echidna and a sibling of such monsters as Cerberus and the Lernaean Hydra.

Orthrus: In Greek mythology, Orthrus (Greek: Ὄρθρος , "Orthros") or Orthus (Greek: Ὄρθος , "Orthos") was, according to the mythographer Apollodorus, a two-headed dog who guarded Geryon's cattle and was killed by Heracles.  He was the offspring of the monsters Echidna and Typhon, and the brother of Cerberus, who was also a multi-headed guard dog.

Echidna (mythology): In Greek mythology, Echidna ( ; Greek: Ἔχιδνα , "She-Viper") was a monster, half-woman and half-snake, who lived alone in a cave.  She was the mate of the fearsome monster Typhon, and known primarily for being the mother of monsters, including many of the most famous monsters of Greek myth.

Cerberus: In Greek mythology, Cerberus ( ; Greek: Κέρβερος "Kerberos" ] ), often called the "hound of Hades", is the monstrous multi-headed dog that guards the gates of the Underworld to prevent the dead from leaving.  Cerberus was the offspring of the monsters Echidna and Typhon, and usually is described as having three heads, a serpent for a tail, and snakes protruding from parts of his body.  Cerberus is primarily known for his capture by Heracles, one of Heracles' twelve labours.

Supporting paragraphs: Cerberus Echidna (mythology)
Answer: Typhon