The herald in the palace of Ithaca who is spared by Odysseus is Medon.
Medon is the faithful herald serving Odysseus’s household in Homer’s Odyssey. During Odysseus’s absence, the suitors occupy the palace and consume its resources while competing for Penelope’s hand. Although Medon is present among them, he is not portrayed as one of the predatory suitors.
Medon proves his loyalty by overhearing the suitors’ plan to ambush and kill Telemachus. He reports the plot to Penelope, allowing her to learn that her son is in danger. His warning distinguishes him from palace figures who cooperate with the suitors.
When Odysseus returns to Ithaca and kills the suitors, Medon hides beneath a chair covered by an ox hide. Telemachus recognizes his goodness and asks Odysseus to spare him. Odysseus agrees, also sparing the bard Phemius. Phemius is therefore another survivor of the palace massacre, but he is a singer, not the herald named in the question. Eumaeus is Odysseus’s loyal swineherd, while Eurymachus is a suitor.