Pulcinella, also known by his alias "Gallo", is number 5 of the Eleven Heralds of the Fatui. Shown in the preview of the Chapter of Teyvat - Plot Preview of Genshin Impact: Footprints (Act VI, Snezhnaya).
When Tartaglia (then known as Ajax) was 14 years old, he was dragged into the Abyss and resurfaced greatly changed by the events that occurred there; he gained unrivaled combat prowess and a knack for wreaking havoc around him. This aroused Pulcinella's curiosity, and she recruited the boy with the Fatui under the pretext of serving the Tsarina as punishment.
There is no clear description of what Pulcinella looks like.
Little is known about Pulcinella's personality, but he seems to be someone quite calculating, since realizing about Tartaglia's great strength and habit of being in the midst of chaos, he decided to recruit him so that the Fatui can further promote their cause. ease, and in turn Tartaglia satiates his appetite for battle. Pulcinella also gives "cautious advice" regarding Tartaglia, calling him trustworthy, but warning against clinging to him.