She was on the list.
That's now how this works.
In Greek mythology, Orthrus (‹See Tfd›Greek: Ὄρθρος, Orthros) or Orthus (‹See Tfd›Greek: Ὄρθος, Orthos) was, according to the mythographer Apollodorus,a two-headed dogwho guarded Geryon's cattle and was killed by Heracles.[1] He was the offspring of the monsters Echidna and Typhon, and the brother of Cerberus, who was also a multi-headed guard dog.[2]