Gravingas is one of the ghost residents of Port Phasmatys. He can be found in what was the town market, waving a placard and protesting about Necrovarus' refusal to allow the townspeople to cross into the next world, although only players who are wearing a ghostspeak amulet or have completed Hard Morytania Tasks can understand him.
During the Ghosts Ahoy quest, Gravingas will ask players to collect signatures for a petition demanding that Necrovarus release the townspeople from their imprisonment. Even after the completion of the quest he will continue to protest and shout anti-Necrovarus slogans, believing people should have an interest in local politics.
Gravingas used to speak on the overworld (not the chatbox) in English instead of ghost, even if the player was not wearing an Amulet of Ghostspeak. This has since been fixed so that he now speaks in ghost in the chatbox and the overworld.
If a player has high enough Prayer, he begins to tell the story of how he came to be the crier of the port, but eventually "woo's away".
Some of the quotes that Gravingas says are excerpts from speeches by Martin Luther King Jr., a civil rights activist who campaigned for an end to discrimination in the USA.